RESOLVED: Alberta AT1 Error 10020

We are currently investigating reports regarding Error 10020 affecting the filing of Alberta AT1 returns from TaxCycle T2. This issue appears to have surfaced following Alberta Finance system updates over the weekend.

The full text of the error is as follows:

Resolution

This error occurs when you attempt to file an AT1 return created in the 2024 T2 module (file extension ending in .2024T2). You must convert the file to using the 2025 T2 module, available since November 2025. For instructions, see the T2 file conversion help topic.