Complete API reference

This page is generated from the authoritative OpenAPI contract. Expand only the section you need; no query parameter or request-body field is left to inference.

Base URL: https://iiproxy.sekkun.co

Download the OpenAPI 3.1 YAML

Availability and authentication

GET /public/v1/ping

Public API liveness probe

Required permissions: Public endpoint

Responses

Status	Description	Content type
200	Service is available	—

POST /oauth2/token

Exchange client credentials for an opaque access token

Required permissions: HTTP Basic (client_id + client_secret)

Request body

application/x-www-form-urlencoded

Field	Type	Rules	Meaning
grant_type	string	required; = client_credentials	Value defined by the API contract.
scope	string	optional	Value defined by the API contract.

Responses

Status	Description	Content type
200	Access token	application/json
401	Guard or validation failure	application/json

POST /public/v1/oauth2/token

Versioned alias for the client-credentials token exchange

Required permissions: HTTP Basic (client_id + client_secret)

Request body

application/x-www-form-urlencoded

Field	Type	Rules	Meaning
grant_type	string	required; = client_credentials	Value defined by the API contract.
scope	string	optional	Value defined by the API contract.

Responses

Status	Description	Content type
200	Access token	application/json
401	Guard or validation failure	application/json

Outgoing invoices

GET /public/v1/outgoing-invoices

List outgoing invoices for the credential-bound tenant

Required permissions: invoices:read

Query parameters

Field	Type	Rules	Meaning
status	string	optional	Return only documents whose unified status equals this value.
documentNumber	string	optional	Case-insensitive substring match against the document number.
from	string (date)	optional	Include documents issued on or after this date.
to	string (date)	optional	Include documents issued on or before this date.
limit	integer	optional; default: 1000; ≥ 1	Maximum number of matching documents returned.

Responses

Status	Description	Content type
200	Invoice list	application/json

POST /public/v1/outgoing-invoices

Create a structured or raw UBL invoice draft

Required permissions: invoices:draft

Request headers

Field	Type	Rules	Meaning
Idempotency-Key	string	required; min 16; max 100	Value defined by the API contract.
IIProxy-Auto-Issue	boolean	optional	Direct-XML equivalent of the JSON issue flag; also requires invoices:issue.
IIProxy-Delivery-Channel	string	optional; AS4 · FISCALIZATION_ONLY	Value defined by the API contract.

Request body

application/json - variant 1

Field	Type	Rules	Meaning
documentNumber	string	optional	Required when numberMode is MANUAL; allocated by Klik Račun when numberMode is AUTO.
numberMode	string	optional; AUTO · MANUAL; default: AUTO	Selects automatic or caller-supplied numbering.
issueDate	string (date)	required	Invoice issue date in YYYY-MM-DD form.
deliveryDate	string (date)	required	Supply or service delivery date in YYYY-MM-DD form.
dueDate	string | null (date)	optional	Payment due date; required by payment models with a remaining balance.
currency	string	optional; default: EUR; min 3; max 3	ISO 4217 currency code.
documentType	string	optional; Invoice · CreditNote · AdvanceInvoice; default: Invoice	Business document type; AdvanceInvoice selects the advance-declaration process.
paymentModel	string	optional; DUE · ADVANCE_AND_BALANCE · ONSITE · ADVANCE_DECLARATION; default: DUE	Determines due-date, immediate-payment, and advance settlement rules.
deliveryChannel	string	optional; AS4 · FISCALIZATION_ONLY; default: AS4	Requested delivery path; Klik Račun may select an authoritative non-AS4 reporting path when recipient discovery requires it.
supplier	object	optional	Optional ownership assertion. Klik Račun only accepts a matching OIB and replaces all supplier data with the credential-bound issuer profile.
supplier.oib	string	optional; pattern: ^[0-9]{11}$	Must equal the OIB bound to the API credential.
customer	object	required	Value defined by the API contract.
customer.partnerId	string (uuid)	optional	Optional Klik Račun partner master-data identifier.
customer.partnerCode	string	optional	Optional caller or master-data partner code.
customer.name	string	required	Legal name; accepted as an alias for fullName.
customer.fullName	string	optional	Legal name; required when name is omitted.
customer.shortName	string	optional	Display name; defaults to the legal name.
customer.oib	string	required; pattern: ^[0-9]{11}$	Croatian personal identification number.
customer.endpointScheme	string	optional; default: 9934; max 16	Electronic-address identifier scheme.
customer.countryCode	string	optional; default: HR; min 2; max 2	ISO 3166-1 alpha-2 country code.
customer.vatId	string	optional	VAT identifier when applicable.
customer.city	string	optional	Value defined by the API contract.
customer.postalCode	string	optional	Value defined by the API contract.
customer.streetAddress	string	optional	Value defined by the API contract.
customer.additionalAddress	string	optional	Value defined by the API contract.
customer.addressDetails	string	optional	Value defined by the API contract.
customer.county	string	optional	Value defined by the API contract.
customer.contactEmail	string (email)	optional	Value defined by the API contract.
lines	array [object]	required; min 1	Value defined by the API contract.
lines.articleId	string (uuid)	optional	Optional Klik Račun article master-data identifier.
lines.code	string	optional	Seller's article or service code.
lines.name	string	required	Line item name.
lines.quantity	number	required; > 0	Value defined by the API contract.
lines.unitCode	string	optional; default: EA; max 16	UNECE unit-of-measure code.
lines.unitPrice	number	required; ≥ 0	Net unit price before VAT.
lines.taxCode	string	required	Klik Račun tax master-data code.
lines.taxRate	number	required; ≥ 0	Applied VAT percentage.
lines.ublTaxCategory	string	optional; default: S; max 16	EN 16931/UBL VAT category code.
lines.ublHrTaxCategory	string	optional	Croatian extension tax-category code when applicable.
lines.taxCategoryCode	string	optional	Optional Klik Račun tax-category code.
lines.classification	object	required	Value defined by the API contract.
lines.classification.value	string	required	KPD classification value.
lines.classification.schemeId	string	optional; = CG; default: CG	Croatian KPD scheme identifier.
lines.classification.schemeVersionId	string	optional	Optional KPD scheme version.
lines.salesAccountId	string (uuid)	optional	Required on every line when splitSalesAccounts is true.
additionalTaxes	array [object]	optional	Value defined by the API contract.
additionalTaxes.code	string	required	Value defined by the API contract.
additionalTaxes.description	string	required	Value defined by the API contract.
additionalTaxes.hrCategory	string	required; HR:PP · HR:PPMV · HR:POVNAK · HR:N	Value defined by the API contract.
additionalTaxes.taxableAmount	number	required; ≥ 0	Value defined by the API contract.
additionalTaxes.rate	number	required; ≥ 0	Value defined by the API contract.
notes	array [string]	optional	Free-form invoice notes; each note is limited to 2,000 characters.
paymentInstructions	object	optional	Value defined by the API contract.
paymentInstructions.meansCode	string	optional; default: 30; pattern: ^(?:[0-9]{1,3}|ZZZ)$	UNCL 4461 payment-means code; 30 and 58 require iban.
paymentInstructions.iban	string	optional	Creditor account IBAN; spaces are removed before validation.
paymentInstructions.bic	string	optional	Creditor bank BIC.
paymentInstructions.accountName	string	optional	Value defined by the API contract.
paymentInstructions.paymentReference	string	optional	Value defined by the API contract.
paymentInstructions.model	string	optional; pattern: ^HR[0-9]{2}$	Croatian payment-reference model.
paymentInstructions.purposeCode	string	optional	Value defined by the API contract.
paymentInstructions.description	string	optional	Value defined by the API contract.
paymentInstructions.terms	string	optional	Value defined by the API contract.
paymentProfileId	string (uuid)	optional	Optional active Klik Račun payment profile; when supplied, its instructions replace paymentInstructions.
initialPayments	array [object]	optional	Payments collected when the document is created; not allowed for DUE invoices.
initialPayments.methodCode	string	required	Payment method code such as TRA
initialPayments.paymentDate	string (date)	required	Date on which the payment occurred.
initialPayments.amount	number	required; > 0	Positive payment amount in the invoice currency.
initialPayments.referenceNumber	string	optional	Bank
initialPayments.note	string	optional	Optional human-readable payment note.
stagedReferences	array [object]	optional	Commercial and supporting-document references inserted with the new draft.
stagedReferences.referenceKind	string	required; RECURRING_CONTRACT · BUYER_CONTRACT · SALES_ORDER · PURCHASE_ORDER · DESPATCH · RECEIPT · TENDER · OFFER · SUPPORTING_DOCUMENT · BUYER_REFERENCE · PROJECT · INVOICED_OBJECT · BUYER_COST_CENTER · PREVIOUS_INVOICE	Determines the EN 16931/UBL reference mapping and whether input is manual or selected from Klik Račun.
stagedReferences.inputMode	string	optional; MANUAL · SYSTEM	Must match the selected reference kind; RECURRING_CONTRACT is SYSTEM and most other kinds are MANUAL.
stagedReferences.internalEntityId	string (uuid)	optional	Required for a SYSTEM reference such as a selected recurring-contract occurrence.
stagedReferences.documentNumber	string	optional	Required for MANUAL references.
stagedReferences.documentDate	string (date)	optional	Referenced document date when applicable.
stagedReferences.description	string	optional	Human-readable reference description.
stagedReferences.externalUrl	string (uri)	optional	External supporting-document URL.
stagedReferences.attachment	object	optional	Value defined by the API contract.
stagedReferences.attachment.name	string	required	Attachment filename.
stagedReferences.attachment.type	string	required	Attachment media type.
stagedReferences.attachment.data	string (byte)	required	Base64-encoded attachment content; decoded size is limited to 5 MiB.
stagedReferences.attachment.size	integer	optional; ≥ 0	Optional decoded byte count used for early size validation.
salesAccountId	string (uuid)	optional	Revenue account to use when the API client has no default account, or to override that default.
splitSalesAccounts	boolean	optional; default: false	When true, every line must supply its own salesAccountId.
issue	boolean	optional; default: false	When true, create the draft and immediately queue guarded issuance; also requires invoices:issue.
advanceApplications	array [object]	optional	Accepted advances to reserve and apply before issuance.
advanceApplications.sourceInvoiceId	string (uuid)	optional	Klik Račun identifier of the accepted advance invoice.
advanceApplications.documentNumber	string	optional	Advance invoice number
advanceApplications.issueDate	string (date)	optional	Advance invoice date
advanceApplications.amount	number	required; > 0	Gross advance amount to reserve and apply.

application/json - variant 2

Field	Type	Rules	Meaning
format	string	required; = UBL	Value defined by the API contract.
ublXml	string	required	Value defined by the API contract.
salesAccountId	string (uuid)	optional	Value defined by the API contract.
deliveryChannel	string	optional; AS4 · FISCALIZATION_ONLY	Value defined by the API contract.
issue	boolean	optional	Value defined by the API contract.
advanceApplications	array [object]	optional	Value defined by the API contract.
advanceApplications.sourceInvoiceId	string (uuid)	optional	Klik Račun identifier of the accepted advance invoice.
advanceApplications.documentNumber	string	optional	Advance invoice number
advanceApplications.issueDate	string (date)	optional	Advance invoice date
advanceApplications.amount	number	required; > 0	Gross advance amount to reserve and apply.

application/xml

Send one complete standalone UBL 2.1/HR-CIUS Invoice or CreditNote XML document. Do not send a Croatian Tax Administration FIS message.

text/xml

Send one complete standalone UBL 2.1/HR-CIUS Invoice or CreditNote XML document. Do not send a Croatian Tax Administration FIS message.

application/ubl+xml

Send one complete standalone UBL 2.1/HR-CIUS Invoice or CreditNote XML document. Do not send a Croatian Tax Administration FIS message.

Responses

Status	Description	Content type
201	Invoice	application/json
202	Invoice created and issuance queued	application/json
422	Guard or validation failure	application/json

GET /public/v1/outgoing-invoices/{invoiceId}

Read one outgoing invoice

Required permissions: invoices:read

Path parameters

Field	Type	Rules	Meaning
invoiceId	string (uuid)	required	Value defined by the API contract.

Responses

Status	Description	Content type
200	Invoice	application/json
404	Guard or validation failure	application/json

PATCH /public/v1/outgoing-invoices/{invoiceId}

Update a structured draft

Required permissions: invoices:draft

Path parameters

Field	Type	Rules	Meaning
invoiceId	string (uuid)	required	Value defined by the API contract.

Request headers

Field	Type	Rules	Meaning
Idempotency-Key	string	required; min 16; max 100	Value defined by the API contract.

Request body

application/json

Field	Type	Rules	Meaning
documentNumber	string	optional	Required when numberMode is MANUAL; allocated by Klik Račun when numberMode is AUTO.
numberMode	string	optional; AUTO · MANUAL; default: AUTO	Selects automatic or caller-supplied numbering.
issueDate	string (date)	required	Invoice issue date in YYYY-MM-DD form.
deliveryDate	string (date)	required	Supply or service delivery date in YYYY-MM-DD form.
dueDate	string | null (date)	optional	Payment due date; required by payment models with a remaining balance.
currency	string	optional; default: EUR; min 3; max 3	ISO 4217 currency code.
documentType	string	optional; Invoice · CreditNote · AdvanceInvoice; default: Invoice	Business document type; AdvanceInvoice selects the advance-declaration process.
paymentModel	string	optional; DUE · ADVANCE_AND_BALANCE · ONSITE · ADVANCE_DECLARATION; default: DUE	Determines due-date, immediate-payment, and advance settlement rules.
deliveryChannel	string	optional; AS4 · FISCALIZATION_ONLY; default: AS4	Requested delivery path; Klik Račun may select an authoritative non-AS4 reporting path when recipient discovery requires it.
supplier	object	optional	Optional ownership assertion. Klik Račun only accepts a matching OIB and replaces all supplier data with the credential-bound issuer profile.
supplier.oib	string	optional; pattern: ^[0-9]{11}$	Must equal the OIB bound to the API credential.
customer	object	required	Value defined by the API contract.
customer.partnerId	string (uuid)	optional	Optional Klik Račun partner master-data identifier.
customer.partnerCode	string	optional	Optional caller or master-data partner code.
customer.name	string	required	Legal name; accepted as an alias for fullName.
customer.fullName	string	optional	Legal name; required when name is omitted.
customer.shortName	string	optional	Display name; defaults to the legal name.
customer.oib	string	required; pattern: ^[0-9]{11}$	Croatian personal identification number.
customer.endpointScheme	string	optional; default: 9934; max 16	Electronic-address identifier scheme.
customer.countryCode	string	optional; default: HR; min 2; max 2	ISO 3166-1 alpha-2 country code.
customer.vatId	string	optional	VAT identifier when applicable.
customer.city	string	optional	Value defined by the API contract.
customer.postalCode	string	optional	Value defined by the API contract.
customer.streetAddress	string	optional	Value defined by the API contract.
customer.additionalAddress	string	optional	Value defined by the API contract.
customer.addressDetails	string	optional	Value defined by the API contract.
customer.county	string	optional	Value defined by the API contract.
customer.contactEmail	string (email)	optional	Value defined by the API contract.
lines	array [object]	required; min 1	Value defined by the API contract.
lines.articleId	string (uuid)	optional	Optional Klik Račun article master-data identifier.
lines.code	string	optional	Seller's article or service code.
lines.name	string	required	Line item name.
lines.quantity	number	required; > 0	Value defined by the API contract.
lines.unitCode	string	optional; default: EA; max 16	UNECE unit-of-measure code.
lines.unitPrice	number	required; ≥ 0	Net unit price before VAT.
lines.taxCode	string	required	Klik Račun tax master-data code.
lines.taxRate	number	required; ≥ 0	Applied VAT percentage.
lines.ublTaxCategory	string	optional; default: S; max 16	EN 16931/UBL VAT category code.
lines.ublHrTaxCategory	string	optional	Croatian extension tax-category code when applicable.
lines.taxCategoryCode	string	optional	Optional Klik Račun tax-category code.
lines.classification	object	required	Value defined by the API contract.
lines.classification.value	string	required	KPD classification value.
lines.classification.schemeId	string	optional; = CG; default: CG	Croatian KPD scheme identifier.
lines.classification.schemeVersionId	string	optional	Optional KPD scheme version.
lines.salesAccountId	string (uuid)	optional	Required on every line when splitSalesAccounts is true.
additionalTaxes	array [object]	optional	Value defined by the API contract.
additionalTaxes.code	string	required	Value defined by the API contract.
additionalTaxes.description	string	required	Value defined by the API contract.
additionalTaxes.hrCategory	string	required; HR:PP · HR:PPMV · HR:POVNAK · HR:N	Value defined by the API contract.
additionalTaxes.taxableAmount	number	required; ≥ 0	Value defined by the API contract.
additionalTaxes.rate	number	required; ≥ 0	Value defined by the API contract.
notes	array [string]	optional	Free-form invoice notes; each note is limited to 2,000 characters.
paymentInstructions	object	optional	Value defined by the API contract.
paymentInstructions.meansCode	string	optional; default: 30; pattern: ^(?:[0-9]{1,3}|ZZZ)$	UNCL 4461 payment-means code; 30 and 58 require iban.
paymentInstructions.iban	string	optional	Creditor account IBAN; spaces are removed before validation.
paymentInstructions.bic	string	optional	Creditor bank BIC.
paymentInstructions.accountName	string	optional	Value defined by the API contract.
paymentInstructions.paymentReference	string	optional	Value defined by the API contract.
paymentInstructions.model	string	optional; pattern: ^HR[0-9]{2}$	Croatian payment-reference model.
paymentInstructions.purposeCode	string	optional	Value defined by the API contract.
paymentInstructions.description	string	optional	Value defined by the API contract.
paymentInstructions.terms	string	optional	Value defined by the API contract.
paymentProfileId	string (uuid)	optional	Optional active Klik Račun payment profile; when supplied, its instructions replace paymentInstructions.
initialPayments	array [object]	optional	Payments collected when the document is created; not allowed for DUE invoices.
initialPayments.methodCode	string	required	Payment method code such as TRA
initialPayments.paymentDate	string (date)	required	Date on which the payment occurred.
initialPayments.amount	number	required; > 0	Positive payment amount in the invoice currency.
initialPayments.referenceNumber	string	optional	Bank
initialPayments.note	string	optional	Optional human-readable payment note.
stagedReferences	array [object]	optional	Commercial and supporting-document references inserted with the new draft.
stagedReferences.referenceKind	string	required; RECURRING_CONTRACT · BUYER_CONTRACT · SALES_ORDER · PURCHASE_ORDER · DESPATCH · RECEIPT · TENDER · OFFER · SUPPORTING_DOCUMENT · BUYER_REFERENCE · PROJECT · INVOICED_OBJECT · BUYER_COST_CENTER · PREVIOUS_INVOICE	Determines the EN 16931/UBL reference mapping and whether input is manual or selected from Klik Račun.
stagedReferences.inputMode	string	optional; MANUAL · SYSTEM	Must match the selected reference kind; RECURRING_CONTRACT is SYSTEM and most other kinds are MANUAL.
stagedReferences.internalEntityId	string (uuid)	optional	Required for a SYSTEM reference such as a selected recurring-contract occurrence.
stagedReferences.documentNumber	string	optional	Required for MANUAL references.
stagedReferences.documentDate	string (date)	optional	Referenced document date when applicable.
stagedReferences.description	string	optional	Human-readable reference description.
stagedReferences.externalUrl	string (uri)	optional	External supporting-document URL.
stagedReferences.attachment	object	optional	Value defined by the API contract.
stagedReferences.attachment.name	string	required	Attachment filename.
stagedReferences.attachment.type	string	required	Attachment media type.
stagedReferences.attachment.data	string (byte)	required	Base64-encoded attachment content; decoded size is limited to 5 MiB.
stagedReferences.attachment.size	integer	optional; ≥ 0	Optional decoded byte count used for early size validation.
salesAccountId	string (uuid)	optional	Revenue account to use when the API client has no default account, or to override that default.
splitSalesAccounts	boolean	optional; default: false	When true, every line must supply its own salesAccountId.
issue	boolean	optional; default: false	When true, create the draft and immediately queue guarded issuance; also requires invoices:issue.
advanceApplications	array [object]	optional	Accepted advances to reserve and apply before issuance.
advanceApplications.sourceInvoiceId	string (uuid)	optional	Klik Račun identifier of the accepted advance invoice.
advanceApplications.documentNumber	string	optional	Advance invoice number
advanceApplications.issueDate	string (date)	optional	Advance invoice date
advanceApplications.amount	number	required; > 0	Gross advance amount to reserve and apply.

Responses

Status	Description	Content type
200	Invoice	application/json
409	Guard or validation failure	application/json

POST /public/v1/outgoing-invoices/{invoiceId}/validate

Validate the effective UBL without issuing it

Required permissions: invoices:issue

Path parameters

Field	Type	Rules	Meaning
invoiceId	string (uuid)	required	Value defined by the API contract.

Request headers

Field	Type	Rules	Meaning
Idempotency-Key	string	required; min 16; max 100	Value defined by the API contract.

Responses

Status	Description	Content type
200	Validation passed	application/json
422	Guard or validation failure	application/json

POST /public/v1/outgoing-invoices/{invoiceId}/issue

Queue guarded routing, transmission, reporting, and fiscalization

Required permissions: invoices:issue

Path parameters

Field	Type	Rules	Meaning
invoiceId	string (uuid)	required	Value defined by the API contract.

Request headers

Field	Type	Rules	Meaning
Idempotency-Key	string	required; min 16; max 100	Value defined by the API contract.

Responses

Status	Description	Content type
202	Asynchronous operation	application/json

GET /public/v1/outgoing-invoices/{invoiceId}/status

Read unified and dimensional invoice status

Required permissions: invoices:read

Path parameters

Field	Type	Rules	Meaning
invoiceId	string (uuid)	required	Value defined by the API contract.

Responses

Status	Description	Content type
200	Invoice status	application/json

GET /public/v1/outgoing-invoices/{invoiceId}/extract-xml/ubl

Download the effective UBL used for issuance

Required permissions: invoices:read

Path parameters

Field	Type	Rules	Meaning
invoiceId	string (uuid)	required	Value defined by the API contract.

Responses

Status	Description	Content type
200	UBL Invoice or CreditNote	application/xml

Reversals, corrections, and advances

POST /public/v1/outgoing-invoices/{invoiceId}/reverse

Create a guarded full reversal

Required permissions: invoices:reverse

Path parameters

Field	Type	Rules	Meaning
invoiceId	string (uuid)	required	Value defined by the API contract.

Request headers

Field	Type	Rules	Meaning
Idempotency-Key	string	required; min 16; max 100	Value defined by the API contract.

Request body

application/json

Field	Type	Rules	Meaning
reason	string	required	Value defined by the API contract.
issueDate	string (date)	optional	Value defined by the API contract.
documentNumber	string	optional	Value defined by the API contract.
numberMode	string	optional; AUTO · MANUAL	Value defined by the API contract.
issue	boolean	optional; default: true	Value defined by the API contract.

Responses

Status	Description	Content type
201	Generated correction documents and optional issue operation	application/json
202	Generated correction documents and optional issue operation	application/json

POST /public/v1/outgoing-invoices/{invoiceId}/correct/preview

Calculate and persist a short-lived correction plan

Required permissions: invoices:correct

Path parameters

Field	Type	Rules	Meaning
invoiceId	string (uuid)	required	Value defined by the API contract.

Request headers

Field	Type	Rules	Meaning
Idempotency-Key	string	required; min 16; max 100	Value defined by the API contract.
IIProxy-Correction-Reason	string	optional; max 2000	Required when the preview body is direct XML.

Request body

application/json - variant 1

Field	Type	Rules	Meaning
issueDate	string (date)	required	Value defined by the API contract.
reason	string	required	Value defined by the API contract.
target	object	required	Structured invoice data from which Klik Račun builds canonical UBL 2.1/HR-CIUS XML.
target.documentNumber	string	optional	Required when numberMode is MANUAL; allocated by Klik Račun when numberMode is AUTO.
target.numberMode	string	optional; AUTO · MANUAL; default: AUTO	Selects automatic or caller-supplied numbering.
target.issueDate	string (date)	required	Invoice issue date in YYYY-MM-DD form.
target.deliveryDate	string (date)	required	Supply or service delivery date in YYYY-MM-DD form.
target.dueDate	string | null (date)	optional	Payment due date; required by payment models with a remaining balance.
target.currency	string	optional; default: EUR; min 3; max 3	ISO 4217 currency code.
target.documentType	string	optional; Invoice · CreditNote · AdvanceInvoice; default: Invoice	Business document type; AdvanceInvoice selects the advance-declaration process.
target.paymentModel	string	optional; DUE · ADVANCE_AND_BALANCE · ONSITE · ADVANCE_DECLARATION; default: DUE	Determines due-date, immediate-payment, and advance settlement rules.
target.deliveryChannel	string	optional; AS4 · FISCALIZATION_ONLY; default: AS4	Requested delivery path; Klik Račun may select an authoritative non-AS4 reporting path when recipient discovery requires it.
target.supplier	object	optional	Optional ownership assertion. Klik Račun only accepts a matching OIB and replaces all supplier data with the credential-bound issuer profile.
target.supplier.oib	string	optional; pattern: ^[0-9]{11}$	Must equal the OIB bound to the API credential.
target.customer	object	required	Value defined by the API contract.
target.customer.partnerId	string (uuid)	optional	Optional Klik Račun partner master-data identifier.
target.customer.partnerCode	string	optional	Optional caller or master-data partner code.
target.customer.name	string	required	Legal name; accepted as an alias for fullName.
target.customer.fullName	string	optional	Legal name; required when name is omitted.
target.customer.shortName	string	optional	Display name; defaults to the legal name.
target.customer.oib	string	required; pattern: ^[0-9]{11}$	Croatian personal identification number.
target.customer.endpointScheme	string	optional; default: 9934; max 16	Electronic-address identifier scheme.
target.customer.countryCode	string	optional; default: HR; min 2; max 2	ISO 3166-1 alpha-2 country code.
target.customer.vatId	string	optional	VAT identifier when applicable.
target.customer.city	string	optional	Value defined by the API contract.
target.customer.postalCode	string	optional	Value defined by the API contract.
target.customer.streetAddress	string	optional	Value defined by the API contract.
target.customer.additionalAddress	string	optional	Value defined by the API contract.
target.customer.addressDetails	string	optional	Value defined by the API contract.
target.customer.county	string	optional	Value defined by the API contract.
target.customer.contactEmail	string (email)	optional	Value defined by the API contract.
target.lines	array [object]	required; min 1	Value defined by the API contract.
target.lines.articleId	string (uuid)	optional	Optional Klik Račun article master-data identifier.
target.lines.code	string	optional	Seller's article or service code.
target.lines.name	string	required	Line item name.
target.lines.quantity	number	required; > 0	Value defined by the API contract.
target.lines.unitCode	string	optional; default: EA; max 16	UNECE unit-of-measure code.
target.lines.unitPrice	number	required; ≥ 0	Net unit price before VAT.
target.lines.taxCode	string	required	Klik Račun tax master-data code.
target.lines.taxRate	number	required; ≥ 0	Applied VAT percentage.
target.lines.ublTaxCategory	string	optional; default: S; max 16	EN 16931/UBL VAT category code.
target.lines.ublHrTaxCategory	string	optional	Croatian extension tax-category code when applicable.
target.lines.taxCategoryCode	string	optional	Optional Klik Račun tax-category code.
target.lines.classification	object	required	Value defined by the API contract.
target.lines.classification.value	string	required	KPD classification value.
target.lines.classification.schemeId	string	optional; = CG; default: CG	Croatian KPD scheme identifier.
target.lines.classification.schemeVersionId	string	optional	Optional KPD scheme version.
target.lines.salesAccountId	string (uuid)	optional	Required on every line when splitSalesAccounts is true.
target.additionalTaxes	array [object]	optional	Value defined by the API contract.
target.additionalTaxes.code	string	required	Value defined by the API contract.
target.additionalTaxes.description	string	required	Value defined by the API contract.
target.additionalTaxes.hrCategory	string	required; HR:PP · HR:PPMV · HR:POVNAK · HR:N	Value defined by the API contract.
target.additionalTaxes.taxableAmount	number	required; ≥ 0	Value defined by the API contract.
target.additionalTaxes.rate	number	required; ≥ 0	Value defined by the API contract.
target.notes	array [string]	optional	Free-form invoice notes; each note is limited to 2,000 characters.
target.paymentInstructions	object	optional	Value defined by the API contract.
target.paymentInstructions.meansCode	string	optional; default: 30; pattern: ^(?:[0-9]{1,3}|ZZZ)$	UNCL 4461 payment-means code; 30 and 58 require iban.
target.paymentInstructions.iban	string	optional	Creditor account IBAN; spaces are removed before validation.
target.paymentInstructions.bic	string	optional	Creditor bank BIC.
target.paymentInstructions.accountName	string	optional	Value defined by the API contract.
target.paymentInstructions.paymentReference	string	optional	Value defined by the API contract.
target.paymentInstructions.model	string	optional; pattern: ^HR[0-9]{2}$	Croatian payment-reference model.
target.paymentInstructions.purposeCode	string	optional	Value defined by the API contract.
target.paymentInstructions.description	string	optional	Value defined by the API contract.
target.paymentInstructions.terms	string	optional	Value defined by the API contract.
target.paymentProfileId	string (uuid)	optional	Optional active Klik Račun payment profile; when supplied, its instructions replace paymentInstructions.
target.initialPayments	array [object]	optional	Payments collected when the document is created; not allowed for DUE invoices.
target.initialPayments.methodCode	string	required	Payment method code such as TRA
target.initialPayments.paymentDate	string (date)	required	Date on which the payment occurred.
target.initialPayments.amount	number	required; > 0	Positive payment amount in the invoice currency.
target.initialPayments.referenceNumber	string	optional	Bank
target.initialPayments.note	string	optional	Optional human-readable payment note.
target.stagedReferences	array [object]	optional	Commercial and supporting-document references inserted with the new draft.
target.stagedReferences.referenceKind	string	required; RECURRING_CONTRACT · BUYER_CONTRACT · SALES_ORDER · PURCHASE_ORDER · DESPATCH · RECEIPT · TENDER · OFFER · SUPPORTING_DOCUMENT · BUYER_REFERENCE · PROJECT · INVOICED_OBJECT · BUYER_COST_CENTER · PREVIOUS_INVOICE	Determines the EN 16931/UBL reference mapping and whether input is manual or selected from Klik Račun.
target.stagedReferences.inputMode	string	optional; MANUAL · SYSTEM	Must match the selected reference kind; RECURRING_CONTRACT is SYSTEM and most other kinds are MANUAL.
target.stagedReferences.internalEntityId	string (uuid)	optional	Required for a SYSTEM reference such as a selected recurring-contract occurrence.
target.stagedReferences.documentNumber	string	optional	Required for MANUAL references.
target.stagedReferences.documentDate	string (date)	optional	Referenced document date when applicable.
target.stagedReferences.description	string	optional	Human-readable reference description.
target.stagedReferences.externalUrl	string (uri)	optional	External supporting-document URL.
target.stagedReferences.attachment	object	optional	Value defined by the API contract.
target.stagedReferences.attachment.name	string	required	Attachment filename.
target.stagedReferences.attachment.type	string	required	Attachment media type.
target.stagedReferences.attachment.data	string (byte)	required	Base64-encoded attachment content; decoded size is limited to 5 MiB.
target.stagedReferences.attachment.size	integer	optional; ≥ 0	Optional decoded byte count used for early size validation.
target.salesAccountId	string (uuid)	optional	Revenue account to use when the API client has no default account, or to override that default.
target.splitSalesAccounts	boolean	optional; default: false	When true, every line must supply its own salesAccountId.
target.issue	boolean	optional; default: false	When true, create the draft and immediately queue guarded issuance; also requires invoices:issue.
target.advanceApplications	array [object]	optional	Accepted advances to reserve and apply before issuance.
target.advanceApplications.sourceInvoiceId	string (uuid)	optional	Klik Račun identifier of the accepted advance invoice.
target.advanceApplications.documentNumber	string	optional	Advance invoice number
target.advanceApplications.issueDate	string (date)	optional	Advance invoice date
target.advanceApplications.amount	number	required; > 0	Gross advance amount to reserve and apply.
documentNumber	string	optional	Value defined by the API contract.
numberMode	string	optional; AUTO · MANUAL	Value defined by the API contract.

application/json - variant 2

Field	Type	Rules	Meaning
format	string	required; = UBL	Value defined by the API contract.
ublXml	string	required	Value defined by the API contract.
salesAccountId	string (uuid)	optional	Value defined by the API contract.
deliveryChannel	string	optional; AS4 · FISCALIZATION_ONLY	Value defined by the API contract.
issue	boolean	optional	Value defined by the API contract.
advanceApplications	array [object]	optional	Value defined by the API contract.
advanceApplications.sourceInvoiceId	string (uuid)	optional	Klik Račun identifier of the accepted advance invoice.
advanceApplications.documentNumber	string	optional	Advance invoice number
advanceApplications.issueDate	string (date)	optional	Advance invoice date
advanceApplications.amount	number	required; > 0	Gross advance amount to reserve and apply.
reason	string	required	Value defined by the API contract.

application/xml

Send one complete standalone UBL 2.1/HR-CIUS Invoice or CreditNote XML document. Do not send a Croatian Tax Administration FIS message.

Responses

Status	Description	Content type
200	Protected correction plan	application/json

POST /public/v1/outgoing-invoices/{invoiceId}/correct

Consume a correction plan once

Required permissions: invoices:correct

Path parameters

Field	Type	Rules	Meaning
invoiceId	string (uuid)	required	Value defined by the API contract.

Request headers

Field	Type	Rules	Meaning
Idempotency-Key	string	required; min 16; max 100	Value defined by the API contract.

Request body

application/json

Field	Type	Rules	Meaning
planId	string (uuid)	required	Value defined by the API contract.
issue	boolean	optional; default: true	Value defined by the API contract.

Responses

Status	Description	Content type
201	Generated correction documents and optional issue operation	application/json
202	Generated correction documents and optional issue operation	application/json

POST /public/v1/outgoing-invoices/{invoiceId}/advance-applications

Reserve an accepted advance against a draft

Required permissions: advances:write

Path parameters

Field	Type	Rules	Meaning
invoiceId	string (uuid)	required	Value defined by the API contract.

Request headers

Field	Type	Rules	Meaning
Idempotency-Key	string	required; min 16; max 100	Value defined by the API contract.

Request body

application/json

Field	Type	Rules	Meaning
sourceInvoiceId	string (uuid)	optional	Klik Račun identifier of the accepted advance invoice.
documentNumber	string	optional	Advance invoice number
issueDate	string (date)	optional	Advance invoice date
amount	number	required; > 0	Gross advance amount to reserve and apply.

Responses

Status	Description	Content type
201	Reserved advance application	—

DELETE /public/v1/outgoing-invoices/{invoiceId}/advance-applications/{applicationId}

Release a draft advance reservation

Required permissions: advances:write

Path parameters

Field	Type	Rules	Meaning
invoiceId	string (uuid)	required	Value defined by the API contract.
applicationId	string (uuid)	required	Value defined by the API contract.

Request headers

Field	Type	Rules	Meaning
Idempotency-Key	string	required; min 16; max 100	Value defined by the API contract.

Responses

Status	Description	Content type
204	Released	—

Outgoing-invoice payments

GET /public/v1/outgoing-invoices/{invoiceId}/payments

List payment evidence and settlement

Required permissions: payments:read

Path parameters

Field	Type	Rules	Meaning
invoiceId	string (uuid)	required	Value defined by the API contract.

Responses

Status	Description	Content type
200	Payments and settlement	—

POST /public/v1/outgoing-invoices/{invoiceId}/payments

Record payment evidence

Required permissions: payments:write

Path parameters

Field	Type	Rules	Meaning
invoiceId	string (uuid)	required	Value defined by the API contract.

Request headers

Field	Type	Rules	Meaning
Idempotency-Key	string	required; min 16; max 100	Value defined by the API contract.

Request body

application/json

Field	Type	Rules	Meaning
methodCode	string	required	Payment method code such as TRA
paymentDate	string (date)	required	Date on which the payment occurred.
amount	number	required; > 0	Positive payment amount in the invoice currency.
referenceNumber	string	optional	Bank
note	string	optional	Optional human-readable payment note.

Responses

Status	Description	Content type
201	Payment recorded	—

POST /public/v1/outgoing-invoices/{invoiceId}/payments/{paymentId}/void

Void payment evidence and queue a reporting correction when required

Required permissions: payments:write

Path parameters

Field	Type	Rules	Meaning
invoiceId	string (uuid)	required	Value defined by the API contract.
paymentId	string (uuid)	required	Value defined by the API contract.

Request headers

Field	Type	Rules	Meaning
Idempotency-Key	string	required; min 16; max 100	Value defined by the API contract.

Responses

Status	Description	Content type
200	Payment voided	—

Incoming invoices and their payments

GET /public/v1/incoming-invoices

List tenant-owned AP documents

Required permissions: incoming:read

Query parameters

Field	Type	Rules	Meaning
status	string	optional	Return only documents whose unified status equals this value.
documentNumber	string	optional	Case-insensitive substring match against the document number.
from	string (date)	optional	Include documents issued on or after this date.
to	string (date)	optional	Include documents issued on or before this date.
limit	integer	optional; default: 1000; ≥ 1	Maximum number of matching documents returned.

Responses

Status	Description	Content type
200	Incoming invoice list	—

GET /public/v1/incoming-invoices/{documentKey}

Read a tenant-owned AP document

Required permissions: incoming:read

Path parameters

Field	Type	Rules	Meaning
documentKey	string	required; min 1; max 1000	Value defined by the API contract.

Responses

Status	Description	Content type
200	Incoming invoice	—
404	Guard or validation failure	application/json

GET /public/v1/incoming-invoices/{documentKey}/extract-xml/ubl

Download the retained incoming UBL

Required permissions: incoming:read

Path parameters

Field	Type	Rules	Meaning
documentKey	string	required; min 1; max 1000	Value defined by the API contract.

Responses

Status	Description	Content type
200	Incoming UBL Invoice or CreditNote	application/xml

GET /public/v1/incoming-invoices/{documentKey}/process-status

Project the recipient business process status from recorded facts

Required permissions: incoming:read

Path parameters

Field	Type	Rules	Meaning
documentKey	string	required; min 1; max 1000	Value defined by the API contract.

Responses

Status	Description	Content type
200	Recipient process status	application/json

POST /public/v1/incoming-invoices/{documentKey}/approve

Record recipient business approval

Required permissions: incoming:respond

Path parameters

Field	Type	Rules	Meaning
documentKey	string	required; min 1; max 1000	Value defined by the API contract.

Request headers

Field	Type	Rules	Meaning
Idempotency-Key	string	required; min 16; max 100	Value defined by the API contract.

Responses

Status	Description	Content type
200	Approved	—

POST /public/v1/incoming-invoices/{documentKey}/reject

Validate and submit recipient rejection

Required permissions: incoming:respond

Path parameters

Field	Type	Rules	Meaning
documentKey	string	required; min 1; max 1000	Value defined by the API contract.

Request headers

Field	Type	Rules	Meaning
Idempotency-Key	string	required; min 16; max 100	Value defined by the API contract.

Request body

application/json

Field	Type	Rules	Meaning
rejectionDate	string (date)	required	Value defined by the API contract.
reasonType	string	required; N · U · O	Value defined by the API contract.
reason	string	required; min 1; max 2000	Value defined by the API contract.

Responses

Status	Description	Content type
202	Rejection submitted	—

GET /public/v1/incoming-invoices/{documentKey}/payments

Read AP payment events and settlement

Required permissions: payments:read

Path parameters

Field	Type	Rules	Meaning
documentKey	string	required; min 1; max 1000	Value defined by the API contract.

Responses

Status	Description	Content type
200	AP payment events and settlement	—

POST /public/v1/incoming-invoices/{documentKey}/payments

Record a dated AP payment event

Required permissions: payments:write

Path parameters

Field	Type	Rules	Meaning
documentKey	string	required; min 1; max 1000	Value defined by the API contract.

Request headers

Field	Type	Rules	Meaning
Idempotency-Key	string	required; min 16; max 100	Value defined by the API contract.

Request body

application/json

Field	Type	Rules	Meaning
methodCode	string	required	Payment method code such as TRA
paymentDate	string (date)	required	Date on which the payment occurred.
amount	number	required; > 0	Positive payment amount in the invoice currency.
referenceNumber	string	optional	Bank
note	string	optional	Optional human-readable payment note.

Responses

Status	Description	Content type
201	AP payment recorded	—

POST /public/v1/incoming-invoices/{documentKey}/payments/{paymentId}/void

Void an AP payment event

Required permissions: payments:write

Path parameters

Field	Type	Rules	Meaning
documentKey	string	required; min 1; max 1000	Value defined by the API contract.
paymentId	string (uuid)	required	Value defined by the API contract.

Request headers

Field	Type	Rules	Meaning
Idempotency-Key	string	required; min 16; max 100	Value defined by the API contract.

Responses

Status	Description	Content type
200	AP payment voided	—

Asynchronous operations

GET /public/v1/events

Stream client-owned operation updates over Server-Sent Events

Required permissions: events:read

Request headers

Field	Type	Rules	Meaning
Last-Event-ID	string	optional; min 1; max 512	Opaque SSE id from the last completely processed event. Omit it for a new stream starting at the current position.

Responses

Status	Description	Content type
200	Server-Sent Events stream of ready and operation.updated events	text/event-stream
400	Guard or validation failure	application/json
401	Guard or validation failure	application/json
403	Guard or validation failure	application/json

GET /public/v1/operations/{operationId}

Read a client-owned asynchronous operation

Required permissions: invoices:read

Path parameters

Field	Type	Rules	Meaning
operationId	string (uuid)	required	Value defined by the API contract.

Responses

Status	Description	Content type
200	Asynchronous operation	application/json
404	Guard or validation failure	application/json