Start building with the BILL API
Integrate with the easy-to-use BILL v3 API and leverage our trusted B2B payments platform to send and receive payments for your business.
Receive real-time event notifications with BILL webhooks. Leverage the BILL Spend & Expense API to build with virtual card and expense management services for real-time visibility and control over the finances of a business.
curl --request POST \
--url 'https://gateway.stage.bill.com/connect/v3/bills' \
--header 'content-type: application/json' \
--header 'devKey: {developer_key}' \
--header 'sessionId: {session_id}' \
--data '{
"vendorId": "{vendor_id}",
"dueDate": "2025-12-31",
"billLineItems": [{
"amount": 149.00,
"description": "USB audio interface"
},
{
"amount": 79.99,
"description": "Drum foot pedal"
}],
"invoice": {
"invoiceNumber": "202501",
"invoiceDate": "2025-12-31"
}
}'
Building blocks for developers
Create custom branded experiences with end-to-end Accounts Payable (AP), Accounts Receivable (AR), virtual card, and expense management workflows at scale.
Safely build and test with API calls in our sandbox environment to confirm your expectations.
Deploy to production when your integration is ready for your customers.
Reference & Recipes
View sample code and step-by-step walkthroughs for popular BILL API use cases.
More API features
Learn about updates made to the BILL v3 API, including BILL webhooks.
Spend & Expense API
Review documentation for integrating with the new BILL Spend & Expense API.
Why integrate with BILL?
Leading payments platform
BILL manages over $250B annually. Use the BILL API to process higher volumes of payments. Leverage our automated sync with a wide range of leading accounting tools, such as QuickBooks, Intacct, NetSuite, and Xero.
Faster & more efficient payments
We facilitate your AP process with faster electronic payments or standard checks. Your AR customers receive faster electronic payments.
Built with your security in mind
All data at rest is protected with encryption, while Transport Layer Security (TLS) provides bank-level protection during transfer. In addition, BILL Spend & Expense is PCI compliant.