CRA Slips Internet Filing Interruption and System Updates for 2026

The Canada Revenue Agency (CRA) will shut down its slip electronic filing systems for maintenance from December 22, 2025, to January 12, 2026. This affects the following: 

• T3, T4, T4A, T4A-NR, T5, T5013, T5018, T2202 and NR4
• T5013 FIN Partnership Financial Return

When the system reopens on January 12, 2026, please note the two following major changes:

• The electronic filing portals will not accept XML files larger than 150 MB in compressed form or those exceeding 1 GB when uncompressed.
• The Internet file transfer portal will now include a detailed Return Error Report for errors identified during validation, making it easier for you to quickly find and correct mistakes.

Read the CRA’s What’s new for 2026 page to learn more.