Error Code Portal
GoogleFirebase Authentication Admin SDKError code

auth/invalid-last-sign-in-time

invalid last sign in time

What does this code mean?

Code auth/invalid-last-sign-in-time · An issue reported by Firebase Authentication Admin SDK.

Official explanation · Original text

The last sign-in time must be a valid UTC date string.

Troubleshooting and diagnostic links

First check that the document's product, version, and environment match your situation.

Source and terms of use

Firebase Admin Authentication API Errors ↗

Creator: Google LLC
License: Creative Commons Attribution 4.0 International
Checked on: 2026-11-12

Modifications: Extracted official error code and description/resolution table; HTML stripped; short code name and original Korean context added. No source-page analytics scripts are redistributed in rendered pages.

Source details · Original licenses and notices