If you owe less than £3,000 for the tax year, HMRC can attempt to collect this underpaid tax by adjusting your PAYE tax code (e.g. through your wages or pension)
Once you have finished the return, please go to the finishing off the tax return section
Then untick the box, that is appropriate:
✅ If you’re happy for HMRC to collect this automatically, leave Box 2 unticked.
❌ Tick Box 2 only if you prefer to pay directly via Self Assessment by 31 January 2026.
Note: This only applies if your return is submitted by 31 October 2025 (paper) or 30 December 2025 (online) and your PAYE income is sufficient.
Box 3 – Collecting Future Income Tax via PAYE (2025–26 Tax Year)
If you expect to owe tax in 2025–26 on things like:
Child Benefit (via the High-Income Child Benefit Charge),
Investment/savings income,
Rental/property income,
Commission or casual work,
HMRC may also collect this through your tax code from 6 April 2025, but only if the total is under £10,000.
✅ Again, leave Box 3 unticked if you want HMRC to collect this via PAYE.
❌ Tick Box 3 only if you prefer to pay through your 2025–26 Self Assessment (due 31 January 2027).
Important Note
Ticking or unticking these boxes does not affect the SA302