> ## Documentation Index > Fetch the complete documentation index at: https://docs.campfire.ai/llms.txt > Use this file to discover all available pages before exploring further. # Mark Invoice as Paid > Mark an invoice as paid, allowing partial payments. This endpoint supports multiple payment methods: - Apply existing transactions as payments - Apply credit memos to reduce the invoice balance - Create manual payments without a transaction The request body should contain at least one of: - transactions: List of transaction payments to apply - credit_memos: List of credit memos to apply - empty_transactions: List of manual payments without transactions ## OpenAPI ````yaml https://api.meetcampfire.com/api/schema?format=json post /coa/api/v1/invoice/{invoice_id}/pay/ openapi: 3.0.3 info: title: Campfire Developer APIs version: 1.0.0 description: > ## Introduction Campfire's developer APIs offer granular access to Campfire's core accounting, revenue recognition, and financial data features. These APIs are designed to be used by developers to build custom integrations, automate workflows, and perform any other programmatic operations. servers: - url: https://api.meetcampfire.com description: Production server security: [] tags: - name: Cash Management description: Operations related to accounts, transactions, and other bank-related data. - name: Core Accounting description: >- Operations related to core accounting data, such as the chart of accounts, entity management, and the general ledger. - name: Revenue Recognition description: >- Operations related to revenue recognition, contract management, and contract data aggregation. - name: Accounts Receivable description: Operations related to invoicing and the AR subledger - name: Accounts Payable description: Operations related to billing and the AP subledger. - name: Financial Statements description: Operations related to financial statement generation and data aggregation. - name: Settings description: Operations related to system and accounting settings configuration. paths: /coa/api/v1/invoice/{invoice_id}/pay/: post: tags: - Accounts Receivable summary: Mark Invoice as Paid description: |- Mark an invoice as paid, allowing partial payments. This endpoint supports multiple payment methods: - Apply existing transactions as payments - Apply credit memos to reduce the invoice balance - Create manual payments without a transaction The request body should contain at least one of: - transactions: List of transaction payments to apply - credit_memos: List of credit memos to apply - empty_transactions: List of manual payments without transactions operationId: coa_api_v1_invoice_pay_create parameters: - in: path name: invoice_id schema: type: integer description: ID of the invoice to mark as paid required: true requestBody: content: application/json: schema: $ref: '#/components/schemas/MarkPaid' examples: MarkInvoiceAsPaidRequest: value: invoice_id: '58700' transactions: - transaction_id: 14728800 transaction_description: Payment from Campfire Software Inc account_id: '2553' account_name: 1100 - Accounts Receivable amount: 883.33 credit_memos: - credit_memo_id: 4029 credit_memo_number: CM-0000007 amount: 150 posted_at: '2025-07-25' empty_transactions: [] summary: Mark Invoice as Paid Request application/x-www-form-urlencoded: schema: $ref: '#/components/schemas/MarkPaid' multipart/form-data: schema: $ref: '#/components/schemas/MarkPaid' responses: '200': content: application/json: schema: $ref: '#/components/schemas/MarkInvoicePaidResponse' description: '' security: - knoxApiToken: [] components: schemas: MarkPaid: type: object properties: transaction_match_id: type: integer nullable: true transactions: type: array items: $ref: '#/components/schemas/MarkPaidTransaction' nullable: true credit_memos: type: array items: $ref: '#/components/schemas/MarkPaidCreditMemo' nullable: true debit_memos: type: array items: $ref: '#/components/schemas/MarkPaidDebitMemo' nullable: true empty_transactions: type: array items: $ref: '#/components/schemas/MarkPaidEmptyTransaction' nullable: true MarkInvoicePaidResponse: type: object description: >- 200 payload for the mark-invoice-paid endpoint. The endpoint returns ids of the records it created rather than the invoice itself. ``auto_created_credit_memos`` is only present when an overpayment produced one. properties: journal_entry_ids: type: array items: type: integer payment_ids: type: array items: type: integer auto_created_credit_memos: type: array items: $ref: '#/components/schemas/MarkInvoicePaidAutoCreatedCreditMemo' required: - journal_entry_ids - payment_ids MarkPaidTransaction: type: object properties: transaction_match_id: type: integer nullable: true transaction_id: type: integer nullable: true transaction_ids: type: array items: type: integer nullable: true account_id: type: integer nullable: true amount: type: number format: double maximum: 1000000000000000000 minimum: -1000000000000000000 exclusiveMaximum: true exclusiveMinimum: true amount_payable: type: number format: double maximum: 1000000000000000000 minimum: -1000000000000000000 exclusiveMaximum: true exclusiveMinimum: true nullable: true credit_account_id: type: integer nullable: true writeoff_account_id: type: integer nullable: true withholding_amount: type: number format: double maximum: 1000000000000000000 minimum: -1000000000000000000 exclusiveMaximum: true exclusiveMinimum: true nullable: true withholding_tax_rate_id: type: integer nullable: true required: - amount MarkPaidCreditMemo: type: object properties: credit_memo_id: type: integer amount: type: number format: double maximum: 1000000000000000000 minimum: -1000000000000000000 exclusiveMaximum: true exclusiveMinimum: true posted_at: type: string format: date required: - amount - credit_memo_id - posted_at MarkPaidDebitMemo: type: object properties: debit_memo_id: type: integer amount: type: number format: double maximum: 1000000000000000000 minimum: -1000000000000000000 exclusiveMaximum: true exclusiveMinimum: true posted_at: type: string format: date required: - amount - debit_memo_id - posted_at MarkPaidEmptyTransaction: type: object properties: account_id: type: integer account_name: type: string amount: type: number format: double maximum: 1000000000000000000 minimum: -1000000000000000000 exclusiveMaximum: true exclusiveMinimum: true payment_date: type: string format: date department_id: type: integer nullable: true tag_ids: type: array items: type: integer memo: type: string nullable: true external_id: type: string nullable: true maxLength: 256 currency: type: string nullable: true amount_in_invoice_currency: type: number format: double maximum: 1000000000000000000 minimum: -1000000000000000000 exclusiveMaximum: true exclusiveMinimum: true nullable: true amount_in_bill_currency: type: number format: double maximum: 1000000000000000000 minimum: -1000000000000000000 exclusiveMaximum: true exclusiveMinimum: true nullable: true withholding_amount: type: number format: double maximum: 1000000000000000000 minimum: -1000000000000000000 exclusiveMaximum: true exclusiveMinimum: true nullable: true withholding_tax_rate_id: type: integer nullable: true required: - account_id - account_name - amount - payment_date MarkInvoicePaidAutoCreatedCreditMemo: type: object properties: id: type: integer credit_memo_number: type: string required: - credit_memo_number - id securitySchemes: knoxApiToken: type: apiKey in: header name: Authorization description: Token-based authentication with required prefix "Token" ````