> ## Documentation Index > Fetch the complete documentation index at: https://docs.streamlinedpayments.com/llms.txt > Use this file to discover all available pages before exploring further. # Get average payment period > See how many days your customers took, on average, to pay the invoices paid off each month, as on your dashboard's Average payment period chart. See [Reports](/guides/reports#average-payment-period). ## OpenAPI ````yaml /api-reference/openapi.yaml get /reports/average_payment_period openapi: 3.0.3 info: title: Streamlined API description: > Access customers, customer applications, customer groups, products, payouts, invoices, transactions, deposit links, and the reports behind your dashboard programmatically through this API, and receive webhooks when deposit links change. All requests must be authenticated with an API key. version: 1.8.0 license: name: Proprietary url: https://streamlinedpayments.com/terms servers: - url: https://api.staging.streamlinedpayments.com/api/v1 description: Sandbox - url: https://api.streamlinedpayments.com/api/v1 description: Production security: - AppIdAuth: [] ApiKeyAuth: [] tags: - name: Customers description: Create, update and delete the businesses you sell to. - name: Customer applications description: >- List the applications your customers submit, and approve them. Approving can also set net terms and export the customer to Shopify. See [Approve customer applications](/guides/customer-applications). - name: Customer groups description: >- Organize customers into groups and manage who's in each one. A group can be linked to a Shopify B2B company. - name: Customer files description: Upload and manage files attached to a customer. - name: Customer addresses description: Manage a customer's addresses and choose their default billing address. - name: Orders description: Create orders, add and remove line items, and schedule them. - name: Invoices description: Create invoices from orders, then list, look up and update them. - name: Transactions description: List transactions and look one up. - name: Payouts description: List payouts, including pending ones, and look one up. - name: Products description: >- Create and update the products and services you sell, import them in bulk, and merge duplicates. - name: Deposit links description: Collect money from a customer before an invoice exists. - name: Webhooks description: >- Register HTTPS endpoints to receive events when something changes. See [Webhooks](/guides/webhooks) for signatures, retries and delivery guarantees. - name: Reports description: >- Read the aging, sales, collections, and customer figures your dashboard and customer pages show. Amounts are in cents, in the currency each response names. See [Reports](/guides/reports) for how each figure is worked out. paths: /reports/average_payment_period: get: tags: - Reports summary: Get average payment period description: >- See how many days your customers took, on average, to pay the invoices paid off each month, as on your dashboard's Average payment period chart. See [Reports](/guides/reports#average-payment-period). operationId: getAveragePaymentPeriodReport parameters: - $ref: '#/components/parameters/ReportStartDate' - $ref: '#/components/parameters/ReportEndDate' responses: '200': description: Successful operation content: application/json: schema: $ref: '#/components/schemas/AveragePaymentPeriod' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' components: parameters: ReportStartDate: name: start_date in: query description: >- First month of the range, as any day in it (`YYYY-MM-DD`). The range can be at most 24 months. required: false schema: type: string format: date ReportEndDate: name: end_date in: query description: Last month of the range, as any day in it (`YYYY-MM-DD`). required: false schema: type: string format: date schemas: AveragePaymentPeriod: type: object properties: data: type: array description: Every month in the range, oldest first. items: type: object properties: month: $ref: '#/components/schemas/ReportMonth' average_days_to_pay: type: integer nullable: true description: >- Average days from issue to payment, for the invoices paid off that month. Null in a month with nothing paid off. `0` means paid on the day of issue. example: 34 median_days_to_pay: type: integer nullable: true description: >- Median days from issue to payment, for the same invoices. A few very old invoices pull the average up but barely move the median. Null when the average is. example: 21 paid_invoice_count: type: integer description: Number of invoices the average covers. example: 6 ReportMonth: type: string description: Month, as `YYYY-MM`, in your account's time zone. example: 2026-10 Error: type: object properties: error: type: string message: type: string responses: BadRequest: description: >- A parameter is malformed, out of range, or not one of its allowed values (`invalid_parameter`). `message` says which. Values aren't ignored, except that `per_page` above 100 is treated as 100. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: invalid_parameter message: weeks must be one of 13, 26, 52 Unauthorized: description: Authentication failed content: application/json: schema: $ref: '#/components/schemas/Error' examples: AuthenticationRequired: value: error: Authentication required message: >- API endpoint requires authentication. Please provide valid X-App-Id and X-Api-Key headers. InvalidCredentials: value: error: Invalid credentials message: >- The provided API credentials are invalid. Please check your X-App-Id and X-Api-Key values. securitySchemes: AppIdAuth: type: apiKey in: header name: X-App-Id description: App ID for authentication ApiKeyAuth: type: apiKey in: header name: X-Api-Key description: API Key for authentication ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.