Self-assessment
Form 11 for 2025: due 31 October, or 18 November on ROS
Last updated 16 October 2026
File your 2025 return, pay the balance and pay 2026 preliminary tax by 31 October 2026. If you pay and file on ROS, it's 18 November 2026.
By the pay-and-file date, three things are due together:
- your 2025 Form 11 tax return
- any balance of tax for 2025
- preliminary tax for 2026
| How you pay and file | Deadline |
|---|---|
| Paper, or not entirely through ROS | Saturday 31 October 2026 |
| Both pay and file through ROS | Wednesday 18 November 2026 |
The extension only applies if you both file and pay through ROS. Filing on ROS but paying another way loses it. If there is nothing to pay, filing on ROS by 18 November is enough.
The ROS extension doesn't move Capital Gains Tax: that is paid by 15 December for sales from January to November.
Our sole trader calculator labels every figure with its Form 11 line, so you can type it straight into ROS.
Work it out
Sources
- Revenue: Pay and file system: how does it work? (checked 25/10/2026)
- Revenue: eBrief No. 034/26: ROS pay and file extended to 18 November 2026 (checked 25/10/2026)
- Revenue: Form 11 2025: Tax Return and Self-Assessment (checked 24/10/2026)
General information, not tax advice. HeyPenny is not a tax agent.