> ## Documentation Index > Fetch the complete documentation index at: https://docs.sequencehq.com/llms.txt > Use this file to discover all available pages before exploring further. # Apply a Credit Note to an Invoice > Allocates an amount from a Credit Note's balance to an Invoice's balance. ## OpenAPI ````yaml invoices.latest.product.live POST /credit-note-applications openapi: 3.0.0 info: title: Invoices description: Create and issue invoices version: '0.1' servers: - url: https://dev.seqhq.io/api description: DEV - url: https://sandbox.sequencehq.com/api description: SANDBOX - url: https://eu.sequencehq.com/api description: PRODUCTION security: [] tags: [] paths: /credit-note-applications: servers: [] parameters: [] post: tags: - Credit Notes summary: Apply a Credit Note to an Invoice description: >- Allocates an amount from a Credit Note's balance to an Invoice's balance. operationId: postCreditNoteApplications parameters: - name: Authorization in: header description: >- Your [API credentials](/reference/authentication). Eg. `Basic {credentials}`. required: true schema: type: string - name: Idempotency-Key in: header description: >- Unique ID for this request (max 255 characters). Retrying with the same ID is safe; the operation runs at most once. required: true schema: type: string - name: Sequence-Version in: header description: Use this header to select an API version required: false schema: type: string enum: - '2024-07-30' requestBody: content: application/json: schema: $ref: >- #/components/schemas/CreateCreditNoteApplicationEndpointCreateCreditNoteApplicationRequestModel example: creditNoteId: af60cab3-812d-4250-a051-0fb7133a00c7 invoiceId: 61b083e0-1faa-47ca-9aeb-6205da8f6c47 amount: 50 currency: USD creditNoteBalanceVersion: 3 invoiceBalanceVersion: 7 examples: CreateCreditNoteApplicationEndpointCreateCreditNoteApplicationRequestModel: summary: '' value: creditNoteId: af60cab3-812d-4250-a051-0fb7133a00c7 invoiceId: 61b083e0-1faa-47ca-9aeb-6205da8f6c47 amount: 50 currency: USD creditNoteBalanceVersion: 3 invoiceBalanceVersion: 7 required: true responses: '201': description: Created content: application/json: schema: $ref: '#/components/schemas/CreditNoteApplicationResponse' example: ledgerTransactionId: 0192c1b6-7f3a-7000-8000-000000000001 creditNoteId: af60cab3-812d-4250-a051-0fb7133a00c7 invoiceId: 61b083e0-1faa-47ca-9aeb-6205da8f6c47 amount: 50 currency: USD appliedAt: '2026-05-28T12:34:56Z' invoiceBalance: value: 150 currency: USD version: 8 creditNoteBalance: value: 50 currency: USD version: 4 examples: CreditNoteApplicationResponse: summary: '' value: ledgerTransactionId: 0192c1b6-7f3a-7000-8000-000000000001 creditNoteId: af60cab3-812d-4250-a051-0fb7133a00c7 invoiceId: 61b083e0-1faa-47ca-9aeb-6205da8f6c47 amount: 50 currency: USD appliedAt: '2026-05-28T12:34:56Z' invoiceBalance: value: 150 currency: USD version: 8 creditNoteBalance: value: 50 currency: USD version: 4 '400': description: Bad Request content: {} '401': description: Unauthorized content: {} '409': description: Conflict content: application/json: schema: $ref: '#/components/schemas/VersionConflictResponse' example: message: >- Balance version mismatch. Re-read current versions and retry. currentInvoiceBalance: value: 150 currency: USD version: 8 currentCreditNoteBalance: value: 50 currency: USD version: 4 examples: VersionConflictResponse: summary: '' value: message: >- Balance version mismatch. Re-read current versions and retry. currentInvoiceBalance: value: 150 currency: USD version: 8 currentCreditNoteBalance: value: 50 currency: USD version: 4 '500': description: Internal Server Error content: {} components: schemas: CreateCreditNoteApplicationEndpointCreateCreditNoteApplicationRequestModel: required: - amount - creditNoteBalanceVersion - creditNoteId - currency - invoiceBalanceVersion - invoiceId type: object example: creditNoteId: af60cab3-812d-4250-a051-0fb7133a00c7 invoiceId: 61b083e0-1faa-47ca-9aeb-6205da8f6c47 amount: 50 currency: USD creditNoteBalanceVersion: 3 invoiceBalanceVersion: 7 properties: creditNoteId: type: string description: The Credit Note to draw from example: af60cab3-812d-4250-a051-0fb7133a00c7 invoiceId: type: string description: The Invoice to apply credit to example: 61b083e0-1faa-47ca-9aeb-6205da8f6c47 amount: type: number description: Amount to allocate from the Credit Note to the Invoice. example: 50 currency: $ref: '#/components/schemas/Currency' description: >- Currency of the amount. Must match the Credit Note and Invoice currency. creditNoteBalanceVersion: type: integer description: Expected current balance version of the Credit Note (for OCC) format: int64 example: 3 invoiceBalanceVersion: type: integer description: Expected current balance version of the Invoice (for OCC) format: int64 example: 7 CreditNoteApplicationResponse: required: - amount - appliedAt - creditNoteBalance - creditNoteId - currency - invoiceBalance - invoiceId - ledgerTransactionId type: object example: ledgerTransactionId: 0192c1b6-7f3a-7000-8000-000000000001 creditNoteId: af60cab3-812d-4250-a051-0fb7133a00c7 invoiceId: 61b083e0-1faa-47ca-9aeb-6205da8f6c47 amount: 50 currency: USD appliedAt: '2026-05-28T12:34:56Z' invoiceBalance: value: 150 currency: USD version: 8 creditNoteBalance: value: 50 currency: USD version: 4 properties: ledgerTransactionId: type: string description: Ledger transaction id that recorded the application example: 0192c1b6-7f3a-7000-8000-000000000001 creditNoteId: type: string example: af60cab3-812d-4250-a051-0fb7133a00c7 invoiceId: type: string example: 61b083e0-1faa-47ca-9aeb-6205da8f6c47 amount: type: number description: Amount applied example: 50 currency: $ref: '#/components/schemas/Currency' appliedAt: type: string format: date-time example: '2026-05-28T12:34:56Z' invoiceBalance: $ref: '#/components/schemas/BalanceResponse' creditNoteBalance: $ref: '#/components/schemas/BalanceResponse' VersionConflictResponse: required: - currentCreditNoteBalance - currentInvoiceBalance - message type: object example: message: Balance version mismatch. Re-read current versions and retry. currentInvoiceBalance: value: 150 currency: USD version: 8 currentCreditNoteBalance: value: 50 currency: USD version: 4 properties: message: type: string description: Human-readable conflict explanation example: Balance version mismatch. Re-read current versions and retry. currentInvoiceBalance: $ref: '#/components/schemas/BalanceResponse' currentCreditNoteBalance: $ref: '#/components/schemas/BalanceResponse' Currency: type: string example: GBP enum: - AED - ARS - AUD - BRL - BGN - CAD - CHF - CLP - CNY - COP - CZK - DKK - EGP - EUR - GBP - HKD - ILS - INR - ISK - JPY - KRW - MXN - NOK - NZD - PLN - SAR - SEK - SGD - THB - USD - UYU - ZAR BalanceResponse: required: - currency - value - version type: object example: value: 150 currency: USD version: 8 properties: value: type: number description: Balance value example: 150 currency: $ref: '#/components/schemas/Currency' description: Balance currency version: type: integer description: Balance version for optimistic concurrency control format: int64 example: 8 ````