> ## Documentation Index > Fetch the complete documentation index at: https://dev.nickel.com/llms.txt > Use this file to discover all available pages before exploring further. # Record a debit memo on a payment link > Adds an amount to what the payment link asks for after it was issued — a returned-check (NSF) fee, a finance charge on a past-due invoice, a misc fee, shipping added to the order. The memo is included in the link's `requestedAmountCents`, listed in its `debitMemos`, and its `description` is shown to your customer on the payment page next to the amount, so the total they are asked to pay is explained. A memo on a link that was already paid reopens it for the memo's amount. Undo with the void endpoint. To lower what is owed, record an external payment instead — a memo only ever raises the amount. Refused on reusable payment links, archived invoices, invoices with a scheduled charge, and invoices synced with QuickBooks (add the charge to the invoice in QuickBooks; it syncs to Nickel). Pass `externalReferenceId` — your own id for the memo, such as the debit memo number in your ERP — to make the call safe to retry: a repeat with the same reference on the same link returns the existing memo instead of creating another. ## OpenAPI ````yaml /nickel-api-docs.yaml post /paymentLink/{paymentLinkId}/debitMemo openapi: 3.0.3 info: title: Nickel API description: >- This is the specification for the Nickel Rest API. The API lets you programmatically interact with the Nickel server. It uses resource oriented URLs, accepts and returns JSON encoded payloads and uses standard HTTP response codes. It is not a direct API to move money, but instead allows you to interact with Nickel as you would on a web interface. termsOfService: https://www.nickel.com/terms-of-service contact: email: support@nickel.com license: name: Apache 2.0 url: https://www.apache.org/licenses/LICENSE-2.0.html version: 1.0.0 servers: - url: https://rest.staging.nickel.com description: Sandbox / Staging - url: https://rest.nickel.com description: Production security: - bearerAuth: [] tags: - name: Payment description: Payments from your customers to you - name: Disbursement description: Payouts made from Nickel to you - name: Payment Link description: A request for payment against an invoice - name: Customer description: A customer record to request payments against - name: Charge Authorization description: >- An authorization for your customer to allow you to charge their payment method directly - name: Webhook description: Create a webhook for nickel to send updates to - name: File description: A file you can use to attach to invoices or debit authorizations - name: Vendor description: Manage vendors for accounts payable - name: Bill description: Bills from vendors and bill payments - name: Bill Payment Method description: >- A merchant's payment methods used to pay bills (bank accounts and cards on file) - name: Vendor Delivery Method description: >- How a vendor receives funds — bank account (ACH), check mailing address, or international wire (SWIFT) details externalDocs: description: Find out more about Nickel url: https://nickel.com paths: /paymentLink/{paymentLinkId}/debitMemo: post: tags: - Payment Link summary: Record a debit memo on a payment link description: >- Adds an amount to what the payment link asks for after it was issued — a returned-check (NSF) fee, a finance charge on a past-due invoice, a misc fee, shipping added to the order. The memo is included in the link's `requestedAmountCents`, listed in its `debitMemos`, and its `description` is shown to your customer on the payment page next to the amount, so the total they are asked to pay is explained. A memo on a link that was already paid reopens it for the memo's amount. Undo with the void endpoint. To lower what is owed, record an external payment instead — a memo only ever raises the amount. Refused on reusable payment links, archived invoices, invoices with a scheduled charge, and invoices synced with QuickBooks (add the charge to the invoice in QuickBooks; it syncs to Nickel). Pass `externalReferenceId` — your own id for the memo, such as the debit memo number in your ERP — to make the call safe to retry: a repeat with the same reference on the same link returns the existing memo instead of creating another. operationId: recordPaymentLinkDebitMemo parameters: - name: paymentLinkId in: path description: ID of the payment link to add the amount to required: true schema: type: string requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/RecordDebitMemoRequest' responses: '200': description: The new memo and the payment link with its raised total content: application/json: schema: $ref: '#/components/schemas/DebitMemoResponse' '400': description: >- Invalid input, or the link cannot take a debit memo: it is a reusable payment link, archived, has a scheduled charge, or is synced with QuickBooks content: application/json: schema: $ref: '#/components/schemas/Error' '403': description: Payment link does not belong to this API token content: application/json: schema: $ref: '#/components/schemas/Error' '404': description: Payment link not found content: application/json: schema: $ref: '#/components/schemas/Error' '409': description: >- `externalReferenceId` is already recorded on this payment link as a debit memo with a different `amountCents` or `description` (`code` is `REFERENCE_CONFLICT`). Reuse a reference only for the same memo, or void the existing one first. content: application/json: schema: $ref: '#/components/schemas/Error' '500': description: Internal server error content: application/json: schema: $ref: '#/components/schemas/Error' default: description: Unexpected error content: application/json: schema: $ref: '#/components/schemas/Error' components: schemas: RecordDebitMemoRequest: type: object required: - amountCents - description properties: amountCents: type: integer format: int64 minimum: 1 description: Amount to add to the payment link, in cents. example: 3500 description: type: string minLength: 1 maxLength: 100 description: >- What the amount is for. Shown to your customer on the payment page, so write it for them. example: Returned check fee externalReferenceId: type: string minLength: 1 maxLength: 255 description: >- Your own id for this memo, used to make the request idempotent. Posting the same `externalReferenceId` on the same payment link again returns the existing memo with `200` instead of creating a second one, as long as `amountCents` and `description` agree with it; if they differ, the request is refused with `409` and code `REFERENCE_CONFLICT`. Voiding a memo releases its reference. example: DM-1042 DebitMemoResponse: required: - debitMemo - paymentLink type: object properties: debitMemo: $ref: '#/components/schemas/DebitMemo' paymentLink: $ref: '#/components/schemas/PaymentLink' Error: required: - error type: object properties: error: type: string description: >- A human-readable error message describing what went wrong. Note that some 500 responses may return a plain text string instead of this JSON object. code: type: string description: >- A stable machine-readable code, present on the errors a client can act on (e.g. `SHARED_ACCOUNT` on a 409 from the ACH debit authorization upload, `REFERENCE_CONFLICT` on a 409 from recording an external payment or a debit memo). Absent otherwise. DebitMemo: required: - id - amountCents - description - voided - createdAt type: object properties: id: type: string example: cmrb2k7w1000hsf02q8d9x3vn amountCents: type: integer format: int64 example: 3500 description: type: string description: Shown to your customer on the payment page next to the amount. example: Returned check fee voided: type: boolean description: >- Whether the memo has been voided. A voided memo counts toward nothing and is not listed on the payment link; it is only returned by the void endpoint. example: false externalReferenceId: type: string nullable: true description: Your own id for the memo, as passed when it was recorded. example: DM-1042 createdAt: type: string format: date-time PaymentLink: required: - id - name - status - url - payments - externalPayments - debitMemos - debitMemoAmountCents - requestedAmountCents - completedAmountCents type: object properties: id: type: string example: clkqzo2y1000cx9tfohoiodq1 requestedAmountCents: type: integer format: int64 description: The total the link asks for, including its live debit memos. example: 12055 name: type: string example: INV-123 dueDate: type: string format: date nullable: true status: type: string example: ACTIVE payments: type: array items: $ref: '#/components/schemas/Payment' externalPayments: type: array description: >- Live payments recorded against this link outside Nickel (a mailed check, cash). Voided records are omitted. They count toward completedAmountCents alongside payments. items: $ref: '#/components/schemas/ExternalPayment' debitMemos: type: array description: >- Live amounts added to this link after it was issued (an NSF fee, a finance charge), oldest first. Voided memos are omitted. They are included in requestedAmountCents. items: $ref: '#/components/schemas/DebitMemo' debitMemoAmountCents: type: integer format: int64 description: >- Sum of debitMemos. requestedAmountCents minus this is the link's own amount. example: 0 customerId: type: string description: >- ID of the customer the payment link belongs to. Omitted for links created in the dashboard without a customer. url: type: string format: uri example: https://nickel.nickelpayments.com/pay/Ahndhz completedAmountCents: type: integer format: int64 feePassthroughPercent: type: integer nullable: true description: >- Percent (0-100) of the card processing fee passed through to the payer for this payment link. null means no per-link override (the customer/organization setting applies). example: 100 creditCardEnabled: type: boolean nullable: true description: >- Whether the payer can pay this link by credit card. null means no per-link override (the organization setting applies). example: true achEnabled: type: boolean nullable: true description: >- Whether the payer can pay this link by ACH/bank transfer. null means no per-link override (the organization setting applies). example: true amountEditable: type: boolean description: Whether the payer can edit the payment amount at checkout. example: false Payment: type: object properties: id: type: string status: type: string example: SUCCEEDED fees: type: array items: $ref: '#/components/schemas/Fee' amountInCents: type: integer format: int64 example: 10000 chargedAmountInCents: type: integer format: int64 example: 10290 platformFeeInCents: type: integer format: int64 example: 290 paymentLinkId: type: string nullable: true paymentMethod: nullable: true allOf: - $ref: '#/components/schemas/PaymentMethod' disbursement: nullable: true allOf: - $ref: '#/components/schemas/Disbursement' refunds: type: array items: $ref: '#/components/schemas/Refund' createdAt: type: number estimatedDisbursementDate: type: string nullable: true ExternalPayment: required: - id - amountCents - paidAt - voided type: object properties: id: type: string example: cmr9zx1bq000gsf02h1d5w4t8 amountCents: type: integer format: int64 example: 2500 paidAt: type: string format: date description: The date the money moved, as you stated it (YYYY-MM-DD). example: '2026-08-30' voided: type: boolean description: >- Whether the record has been voided. A voided record counts toward nothing and is not listed on the payment link; it is only returned by the void endpoint. example: false externalReferenceId: type: string nullable: true description: >- Your own id for this money, as passed when the record was created. Null when none was given (records made in the Nickel dashboard). example: txn_8f3a2c Fee: type: object properties: type: type: string example: CREDIT_CARD_FEE amountInCents: type: integer format: int64 example: 290 PaymentMethod: type: object properties: id: type: string type: type: string enum: - ACH - Card achDetails: nullable: true allOf: - $ref: '#/components/schemas/ACHDetails' cardDetails: nullable: true allOf: - $ref: '#/components/schemas/CardDetails' billingDetails: nullable: true allOf: - $ref: '#/components/schemas/BillingDetails' Disbursement: type: object properties: id: type: string status: type: string example: PENDING amountInCents: type: integer format: int64 example: 10000 bankName: type: string example: JP Morgan Chase accountNumberLastFour: type: string paymentIds: type: array items: type: string example: clkqzo2y1000cx9tfohoiodq1 createdAt: type: string format: date nullable: true paidAt: type: string format: date nullable: true Refund: type: object properties: id: type: string amountCents: type: integer format: int64 example: 515 refundDate: type: string format: date-time voided: type: boolean ACHDetails: type: object properties: bankName: type: string example: JP Morgan Chase routingNumber: type: string accountNumberLastFour: type: string CardDetails: type: object properties: brand: type: string nullable: true example: visa last4: type: string nullable: true holderName: type: string nullable: true expMonth: type: string nullable: true example: '2' expYear: type: string nullable: true example: '2030' BillingDetails: type: object properties: name: type: string nullable: true companyName: type: string nullable: true street: type: string nullable: true city: type: string nullable: true state: type: string nullable: true zip: type: string nullable: true email: type: string nullable: true securitySchemes: bearerAuth: type: http scheme: bearer ````