---
agentTools:
  projectIndex: https://developer.bill.com/llms.txt
---

# Use UUIDs in the Spend & Expense API

In February 2025, BILL introduced UUIDs in the Spend & Expense API for further improving its security standards. All API responses include both `id` and `uuid` values.

As of July 9, 2025, the Spend & Expense `id` values are being deprecated. Both `id` and `uuid` values will continue to be available in all API responses. We strongly recommend that you use `uuid` instead of `id` in all your Spend & Expense API operations.