How it works
An invoice carries a number, issue and due dates, the customer, line items with quantities, prices and accounts, tax lines and a total. In accrual accounting it creates a receivable and revenue when issued. Payments, credit notes and write-offs reduce the balance until it reaches zero. Many jurisdictions set legal requirements for invoice content and numbering.
Example
A consulting firm issues invoice INV-1042 for 20 hours at $150, plus 8% tax, due in 30 days. When the client pays $3,240, the invoice is marked paid and the receivable clears.
In integrations
Invoices are the most requested finance object. The Unify Accounting API is designed to create, read and update invoices across ledgers, with validation of accounts, tax codes and currencies before submit and idempotency keys on writes. The invoicing automation solution shows the full flow. Invoices touch revenue, tax and cash at once, so customers notice every error. Validate before writing, keep your invoice and the ledger's linked by id, and never create one twice.