Last updated: Jun 29, 2026, 4:03 PM
Learn what causes the "Authentication failed due to an improper request" error in Toast and how to fix it, including steps for Toast Payroll users.
If you see the error "Authentication failed due to an improper request; please try again." when logging in to Toast, it means the email address or password you entered wasn't recognized. This article explains what the error means and how to fix it yourself, including what to do if you were recently added to Toast Payroll.
The error "Authentication failed due to an improper request; please try again." means the credentials used to log in were not recognized. In other words, the email address, password, or other information entered is incorrect or not found on file.
This is a credential mismatch, not a problem with the Toast system itself. In most cases you can resolve it yourself with the steps below.
To fix the authentication failed error, work through these steps in order:
If selecting Forgot password? returns its own error, see the section on Toast Payroll below.
Login can fail even when your password looks correct because your browser autofilled outdated saved credentials. Saved logins are the most common cause of this error.
Type your email address and password manually, uncheck any "Remember me" boxes, and try a private or Incognito window in Google Chrome. If you're on a phone or tablet, switch to a desktop or laptop, which is easier to troubleshoot.
If the authentication failed error started after you were added to Toast Payroll, it usually means you haven't completed unified login. Unified login lets you use the same email address and password for Toast Web and Toast Payroll, and accounts that haven't logged in since 2025 may need to be re-invited to set it up.
When this is the cause, the Forgot password? process often returns an error too. To fix it, ask your manager to resend your invite. In Toast Payroll, a manager can go to the Team page and select the envelope icon next to your name to reinvite you. Once you select the Log in link in the new invite, you can set your password. For more, see Unified Login Experience for Toast Web and Toast Payroll.
If you still can't log in after re-entering your credentials, resetting your password, and clearing your cache, the issue may need a manager or Toast Customer Care. For a full set of login error paths — including locked accounts, expired links, and multi-factor authentication problems — see Log in to Toast: Troubleshoot Login.
Before you contact Customer Care, gather the exact error message text or a screenshot, the email address you're trying to use, and the browser and device you're on. To update the email address or password on your account once you can log in, see Log in to Toast: Update Your Account.