openapi: 3.0.1
info:
  title: Numeral Customers API
  description: REST API for the Numeral (Numeral HQ) sales-tax compliance platform. Calculate real-time sales tax by customer location, record transactions and refunds, and manage products and customers. Registrations, nexus monitoring, filing, and remittance are delivered as managed platform services on top of the data captured through this API. Not affiliated with Numeral (numeral.io), an unrelated payment operations company.
  termsOfService: https://www.numeral.com/terms
  contact:
    name: Numeral Support
    url: https://www.numeral.com/
  version: '2026-03-01'
servers:
- url: https://api.numeralhq.com
  description: Numeral production API
security:
- bearerAuth: []
tags:
- name: Customers
paths:
  /tax/customers:
    post:
      operationId: createCustomer
      tags:
      - Customers
      summary: Create a new customer and optionally mark as tax exempt.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CustomerRequest'
      responses:
        '200':
          description: The created customer.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CustomerResponse'
  /tax/customers/{customer_id}:
    get:
      operationId: getCustomer
      tags:
      - Customers
      summary: Retrieve a specific customer.
      parameters:
      - name: customer_id
        in: path
        required: true
        schema:
          type: string
      - name: id_type
        in: query
        required: false
        schema:
          type: string
          enum:
          - id
          - reference_customer_id
        description: Whether customer_id is Numeral's id or your reference_customer_id.
      responses:
        '200':
          description: The requested customer.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CustomerResponse'
    delete:
      operationId: deleteCustomer
      tags:
      - Customers
      summary: Delete a specific customer.
      parameters:
      - name: customer_id
        in: path
        required: true
        schema:
          type: string
      responses:
        '200':
          description: Deletion confirmation.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/DeletedResource'
components:
  schemas:
    CustomerResponse:
      type: object
      properties:
        id:
          type: string
        object:
          type: string
        reference_customer_id:
          type: string
        name:
          type: string
        email:
          type: string
        is_tax_exempt:
          type: boolean
    DeletedResource:
      type: object
      properties:
        object:
          type: string
        deleted_at:
          type: string
          format: date-time
    CustomerRequest:
      type: object
      properties:
        name:
          type: string
        email:
          type: string
        is_tax_exempt:
          type: boolean
        reference_customer_id:
          type: string
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: Provide your Numeral API key as a Bearer token in the Authorization header.