Xero FAQsHow to Create an Invoice in Xero Using API?You can create invoices in Xero using the Xero Accounting API by sending invoice details such as contact, line items, tax type, due date, currency, and invoice status to the invoice endpoint.This is useful when businesses want to automatically create Xero invoices from CRM, eCommerce platforms, SaaS products, ERP systems, or custom applications.A Xero invoice API request usually includes:– Customer or contact details – Invoice date – Due date – Line items – Quantity and unit price – Account code – Tax type – Currency – Invoice statusCommon API invoice creation issues include:– Missing contact ID – Incorrect account code – Invalid tax type – Wrong invoice status – Currency mismatch – Authentication or token errors – Duplicate invoice numbersBefore using the Xero API for invoice creation, developers should set up a Xero developer app, configure OAuth authentication, test API calls in a demo company, and validate all required invoice fields.For businesses that create invoices from multiple systems, a custom Xero API integration can help manage validation, error logs, retry logic, and automated invoice posting.