> ## Documentation Index
> Fetch the complete documentation index at: https://docs.monk.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Update Customer

> Update a customer. At least one field required.

**Scope:** `customers:write`


## OpenAPI

````yaml /openapi/customers.yaml patch /v1/customers/{customerId}
openapi: 3.1.0
info:
  title: Customers API
  version: '1.0'
servers:
  - url: https://api.monk.com
    description: Production
  - url: https://api-sandbox.monk.com
    description: Sandbox
security:
  - bearerAuth: []
paths:
  /v1/customers/{customerId}:
    patch:
      summary: Update Customer
      description: Update a customer. At least one field required.
      operationId: updateCustomer
      parameters:
        - $ref: '#/components/parameters/customerId'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                name:
                  type: string
                legalName:
                  type:
                    - string
                    - 'null'
                  description: Pass `null` to clear
                tags:
                  type: array
                  items:
                    type: string
                  description: Replaces existing tags
                externalCustomerId:
                  type: string
                paymentProviderId:
                  type: string
                  description: Stripe customer ID (`cus_xxx`). Requires `provider`.
                provider:
                  type: string
                  enum:
                    - stripe
                  description: Payment provider. Requires `paymentProviderId`.
                paymentMethodId:
                  type: string
                  description: >
                    Stripe Payment Method ID (`pm_xxx`). Sets the customer's
                    default payment method on file.

                    Monk retrieves payment method details (last4, brand, type)
                    from Stripe automatically.

                    Requires `paymentMethodType`. Requires the org to have a
                    Stripe integration configured.
                paymentMethodType:
                  type: string
                  enum:
                    - card
                    - us_bank_account
                  description: >-
                    Type of payment method. Required when `paymentMethodId` is
                    provided.
      responses:
        '200':
          description: Customer updated
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    $ref: '#/components/schemas/Customer'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
        '409':
          description: Payment provider customer already linked to another customer
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '422':
          description: >
            Validation error. Possible error codes:

            - `VALIDATION_ERROR` — request body validation failed

            - `STRIPE_NOT_CONFIGURED` — org has no Stripe integration (required
            for `paymentMethodId`)

            - `PAYMENT_METHOD_INVALID` — could not retrieve payment method from
            Stripe (invalid `pm_xxx`)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
components:
  parameters:
    customerId:
      name: customerId
      in: path
      required: true
      schema:
        type: string
  schemas:
    Customer:
      type: object
      properties:
        id:
          type: string
        name:
          type: string
        legalName:
          type:
            - string
            - 'null'
        tags:
          type: array
          items:
            type: string
        isPaused:
          type: boolean
        pausedAt:
          type:
            - string
            - 'null'
        pausedUntil:
          type:
            - string
            - 'null'
          format: date
          description: >-
            Date when customer-level invoice sending resumes automatically
            (`YYYY-MM-DD`), or `null` for no auto-resume date.
        metadata:
          type: object
          properties:
            externalCustomerId:
              type:
                - string
                - 'null'
            externalCompanyIds:
              type: array
              items:
                type: string
        externalIds:
          type: array
          items:
            $ref: '#/components/schemas/ExternalId'
        billingContacts:
          type: array
          description: >-
            Customer-level billing contacts (`accounts_payable` / Accounts
            Payable). Does not include contract- or invoice-specific contacts.
          items:
            $ref: '#/components/schemas/BillingContact'
        createdAt:
          type: string
          format: date-time
        updatedAt:
          type: string
          format: date-time
    ErrorResponse:
      type: object
      properties:
        error:
          type: object
          properties:
            message:
              type: string
            code:
              type: string
    ExternalId:
      type: object
      properties:
        provider:
          type: string
          enum:
            - hubspot
            - quickbooks
            - stripe
            - salesforce
            - netsuite
        entityType:
          type: string
          enum:
            - customer
        id:
          type: string
    BillingContact:
      type: object
      properties:
        name:
          type: string
        email:
          type: string
          format: email
        phone:
          type:
            - string
            - 'null'
  responses:
    Unauthorized:
      description: Invalid or missing API key
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
    NotFound:
      description: Resource not found
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer

````