PB-TRKPKG-ERR-7600 on the Sandbox EnvironmentΒΆ
If you are testing the Track a Package API on the Sandbox environment and encounter PB-TRKPKG-ERR-7600, Invalid PackageIdentifier provided, make sure that you are passing the tracking number for a live USPS label when issuing the API call. The Tracking API in the Sandbox environment works only with Production labels. Do not pass the tracking number for a label created in the Sandbox environment.