United Kingdom · HMRC
Form SA100 — Self Assessment Tax Return
Form SA100 is the main Self Assessment paper tax return for reporting income, claiming reliefs and calculating UK tax for the year.
Fill SA100 now — free to try
Filled entirely on your computer. Your National Insurance number and personal details are never uploaded.
Who needs SA100?
People in Self Assessment who file on paper — note the earlier 31 October paper deadline; most filers now use HMRC online services.
How to fill it with DocsArc
- Open SA100 in the DocsArc workspace with one click above.
- Click any field and type — form fields are detected automatically, and you can add text anywhere.
- Sign it if needed: draw, type or upload your signature, with an automatic date line.
- Save or print. The finished PDF never left your computer.
Frequently asked questions
Can everyone file the paper SA100?
HMRC encourages online filing and restricts paper copies in some years — check the official page for current paper-filing rules.
What is the paper deadline?
Normally 31 October after the end of the tax year, versus 31 January for online returns.
Always verify you have the current version: official HMRC page
Contains public sector information licensed under the Open Government Licence v3.0. DocsArc is an independent tool and is not affiliated with HMRC.