Accounting Software API Integration: Xero and QuickBooks
Accounting software API integration connects your application to your accounting platform — automating the creation of invoices, syncing customer records, reconciling payments, and eliminating manual data entry between business systems. Finance automation reduces errors, saves time, and gives your accountant accurate real-time data.
What You Can Automate
- Creating invoices automatically when orders are completed or projects reach billing milestones
- Marking invoices as paid when payments are received via your payment gateway
- Syncing customer/contact records between your CRM and accounting software
- Importing bank transactions for reconciliation
- Generating expense records from procurement data
- Pulling financial reports programmatically for dashboards
Xero API
Xero's OAuth 2.0 REST API provides access to invoices, contacts, accounts, bank transactions, reports, and more. Well-documented, good rate limits (60 API calls per minute per organisation). Xero is the dominant small business accounting platform in the UK and ANZ regions.
QuickBooks API
Intuit's QuickBooks Online API covers invoices, customers, payments, expenses, and reports. OAuth 2.0 authentication. QuickBooks dominates in the US market — integrations serving US customers should support QuickBooks.
Integration Considerations
- Tax codes and VAT rates must be mapped correctly between systems
- Currency handling for multi-currency businesses
- Chart of accounts mapping — your nominal codes must align
- Test in sandbox environments before connecting to live accounting data