QuickBooks Online Sync Error | Application authentication failed

What's happening

This is a QuickBooks Online (QBO) authentication failure coming back from Intuit:

QBO reply: 401 "Authorization Failure" / code 120 → "Access Denied"

Your payload looks fine for a bill. If it were malformed, you would see a 400 with field-level errors instead of a 401.

What this usually means

• The QBO connection was disconnected or revoked (for example, an admin removed the app, changed permissions, or connected a different company file).
• The OAuth refresh token expired (after 120–180 days of no successful refresh) or was invalidated by Intuit.
• The sync attempted to reach QBO with a stale realm/company ID (for example, if the customer switched companies and didn't re-link).
• Less common: an Intuit service/account lock or permission scope mismatch on the QBO side.

How to resolve

1. Disconnect and reconnect QBO to Ramp:
   • Go to Accounting > Settings.
   • Under the Danger Zone tab, click Disconnect QuickBooks.
2. Then, from the Accounting page, reconnect your ERP:
   • Follow the setup flow and, during the Intuit popup, confirm the company file name is the correct one.
   • Complete the connection.
3. If needed, refer to the QuickBooks Online Overview page for the setup guide.
4. Once reconnected, go back to the failed transactions and click Retry Sync (for card transactions, go to the Card Transactions tab; for bills, go to Bill Pay).