Create a new invoice

Creates a new invoice from a potential invoice. A potential invoice represents billable items (tasks, products, subscriptions, express quotations) that are ready to be invoiced.

How invoice creation works:

First, retrieve available potential invoices using GET /billing/potential-invoices
Review and customize the potential invoice details if needed (adjust billing periods, skip tasks, add manual positions)
Create the invoice using this endpoint with the potential invoice ID
The system automatically:
- Generates a sequential invoice number in the format: {ORG}{PRJ}-{YY}{MM}-{NNN}
- Calculates all amounts, taxes, and fees
- Marks tasks, subscriptions, and express quotations as billed
- Updates project billing status
- Handles interim payments

What happens after creation:

The invoice is created in status “New” (not yet sent)
All billable items included in the invoice are marked as billed
The invoice appears in the “New” invoices grid
You can then send the invoice using the invoice sending endpoints

Potential Invoice ID Format: The potentialInvoiceId follows the format: {type}::{projectId}::{dateFrom}::{dateTo}

Type: One of Mixed, Subscription, TimeBased, ExpressQuotation, SingleProject, InterimPayment
ProjectId: UUID of the project
DateFrom/DateTo: Dates in YYYY-MM-DD format Example: SingleProject::0e9d033a-ab41-4212-8637-66c4e3b01fe2::2025-10-01::2025-10-31

What is returned:

Invoice ID (UUID) - Use this to reference the invoice in other endpoints
Invoice number - The official sequential invoice number for accounting

POST/billing/invoices

Authorization

AuthorizationOAuth2 access token · headerrequired

Scopes:api:write

AuthorizationBearer token (JWT) · headerrequired

Query parameters

fieldsToReturnstring

Comma-separated list of top-level response fields to return. Overrides the endpoint compact default unless responseShape=full is used.

responseShapestring

Advanced override. Omit for the endpoint compact default. Use full only when you need the complete endpoint response, including nested fields that are not selectable with fieldsToReturn.

Allowed:compactfull

Header parameters

LT-Response-Shapestring

Advanced override. Set to full only when you need the complete endpoint response, including nested fields that are not selectable with fieldsToReturn.

Allowed:full

Request body

requiredapplication/json

Potential invoice identifier to create invoice from

potentialInvoiceIdstringrequired

Potential invoice identifier in the format: `{type}::{projectId}::{dateFrom}::{dateTo}`. The type can be one of: Mixed, Subscription, TimeBased, ExpressQuotation, SingleProject, InterimPayment. Dates must be in YYYY-MM-DD format. Example: `SingleProject::0e9d033a-ab41-4212-8637-66c4e3b01fe2::2025-10-01::2025-10-31`. To get available potential invoices, use the GET /billing/potential-invoices endpoint.

Responses

200Invoice created successfully

idstringrequired

Unique identifier (UUID) of the created invoice

numberstringrequired

Invoice number in the format: `{ORG}{PRJ}-{YY}{MM}-{NNN}`. This is the official sequential invoice number used for accounting and customer communication.

400Invalid potential invoice ID or validation errors

401Unauthorized - Invalid or missing authentication token

403Forbidden - Insufficient API scopes or permissions

Request

curl -X POST "https://leadtime.app/api/public/billing/invoices" \
  -H "Authorization: Bearer YOUR_ACCESS_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
  "potentialInvoiceId": "SingleProject::0e9d033a-ab41-4212-8637-66c4e3b01fe2::2025-10-01::2025-10-31"
}'

const response = await fetch("https://leadtime.app/api/public/billing/invoices", {
  method: "POST",
  headers: {
    "Authorization": "Bearer YOUR_ACCESS_TOKEN",
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
  "potentialInvoiceId": "SingleProject::0e9d033a-ab41-4212-8637-66c4e3b01fe2::2025-10-01::2025-10-31"
})
});

import requests

response = requests.post(
    "https://leadtime.app/api/public/billing/invoices",
    headers={
        "Authorization": "Bearer YOUR_ACCESS_TOKEN",
        "Content-Type": "application/json"
    },
    json={
  "potentialInvoiceId": "SingleProject::0e9d033a-ab41-4212-8637-66c4e3b01fe2::2025-10-01::2025-10-31"
},
)

Response

{
  "id": "123e4567-e89b-12d3-a456-426614174000",
  "number": "ACME01-2510-001"
}