SA100 TR 8 Box 22: How do I sign my tax return?
If you are submitting your tax return online, you do not need to sign it. You would only need to sign it if you are submitting a paper return.
If you are submitting a paper return, you can download a copy at the bottom of the Report page.
To do this, you need to click REPORT:
Then scroll to the bottom of that page and click DOWNLOAD TAX RETURN AS PDF: