A 0T tax code (zero-T) means you get no Personal Allowance at all, no tax-free slice of pay. Unlike a BR code, which taxes everything at a flat 20%, a 0T code taxes your income across the normal bands (basic, then higher, then additional) but starting from the very first pound.
This is part of our UK tax codes explained series.
What does 0T mean?
The 0 says your tax-free allowance is zero. The T means there are other items in your code that HMRC needs to review. Put together, 0T removes your £12,570 allowance entirely and applies the standard rate bands from £0 of income on that source.
Why do I have a 0T tax code?
Common reasons include:
- You started a new job and gave no P45 and did not complete the new-starter checklist, so HMRC has no allowance details yet.
- Your Personal Allowance is fully used elsewhere (for example against a higher pension or another job).
- Your income is over £125,140, at which point the Personal Allowance has tapered to nil.
- It can appear on a final payment from an old employer after your leaving date.
0T versus BR and emergency codes
It helps to see the three side by side:
| Code | Allowance | How it taxes |
|---|---|---|
| BR | None | Flat 20% on everything |
| 0T | None | Normal bands (20% → 40% → 45%) from £1 |
| 1257L W1/M1 | £12,570 | Full allowance, but each period taxed in isolation |
So 0T is harsher than BR for higher earners (it can push income into 40% and 45%), and harsher than an emergency code because it removes your allowance altogether.
What to do if the code is wrong
If you think your tax code is wrong, do not just wait, an incorrect code is corrected from the date HMRC updates it, and any over- or under-payment is squared up afterwards. Steps to take:
- Check your latest tax code notice (the "PAYE Coding Notice", form P2) in your HMRC personal tax account. It shows how the code was built up.
- Compare it to your real situation, one job or several, any benefits in kind, untaxed income, or earlier-year underpayments being collected.
- If you have just one job and see 0T, you are almost certainly missing your allowance, give HMRC or your employer your starter details so the right code can be issued.
- Tell HMRC if anything is out of date, online, via the HMRC app, or by phone. They will issue a revised code to your employer.
- Watch your next payslip to confirm the new code has been applied and any refund has come through.
Frequently asked questions
Will I get a refund if my 0T code was wrong?
Usually yes. Once the correct code is applied, overpaid tax is normally repaid through your pay (on a cumulative code) or reconciled by HMRC after the tax year.
Is 0T the same as BR?
No. Both give no allowance, but BR taxes everything at a flat 20%, whereas 0T uses the normal bands from the first pound, so high earners pay more under 0T.
Why is my bonus taxed under 0T?
A payment made after you have left an employer is often run through a 0T code because your allowance details have ended. Any over-deduction is sorted out afterwards.
Think your tax code is wrong? It is one of the most common payroll errors, and HMRC will not always spot it for you. Zmartly's Self Assessment and personal tax team can check your code against your circumstances and deal with HMRC on your behalf. Get in touch for a free review, or book a free Tax Health Check.
