Tax codes one by one
0T tax code
Zero allowance on this job or pension, either because it is used up or because the employer lacks your details.
0T takes more over the year
£2,516.00
| 1257L | 0T | |
|---|---|---|
| Tax-free amount | £12,570 | £0 |
| Tax, first month | £190.20 | £400.00 |
| Tax over the year | £2,284.00 | £4,800.00 |
| Take-home after tax | £21,716 | £19,200 |
Same pay every month, HMRC’s cumulative method, Income Tax only (no National Insurance).
0T means the employer or pension provider gives you no tax-free pay at all. Unlike BR, it does not charge one flat rate: the normal bands still apply, so the first slice of pay is taxed at 20%, and the higher rates follow if the pay is large enough. GOV.UK gives two reasons for it: your Personal Allowance is already fully used, or you started a new job and the employer does not have the details needed to give you a proper code. On a salary of £24,000 paid monthly, 0T takes £4,800.00 over the year, against £2,284.00 with 1257L: a difference of £2,516.00, which is the tax on the £12,570 allowance you are not getting. Scottish taxpayers see S0T and Welsh taxpayers C0T. When 0T is followed by W1, M1 or X, each pay is taxed on its own and nothing comes back until HMRC issues a new code. If your allowance is not really used up, check your record in your HMRC online account.
0T or NT on a pay
Tax each month with 0T
£400.00
| With 1257L | £190.33 |
| With NT | £0.00 |
| With BR | £400.00 |
Rules read on HMRC’s texts by Radif Partners · Editorial policy · Method
Why an employer uses 0T
The employer guidance on tax codes describes 0T as tax taken from all income with no Personal Allowance. Payroll offices meet it in four situations:
- Missing details. A new employee has not handed over a P45 or enough information to work out a code. The starter checklist exists to avoid this: statement A, B or C gives the employer a code with an allowance, or BR.
- Payments after leaving. HMRC's P9X notice says that once a P45 has been given, later payments are taxed with 0T, S0T or C0T on a non-cumulative basis.
- A one-off payment. GOV.UK's guidance for employers who pay someone only once tells them to use 0T and to run it on a week 1 or month 1 basis.
- Allowance used up. High income or deductions in your code leave nothing to give, so HMRC sends 0T to the employer itself.
The first three are temporary or one-off. The fourth is a real code that can stay for the whole tax year.
What 0T takes from a monthly pay
On a month 1 basis, the payroll applies one twelfth of each band to the month's pay, with no free pay. For 2026 to 2027, that means a twelfth of the £37,700 basic rate band at 20%, then the higher rate on anything above it in the same month. The table compares the first month on 0T M1 with the same pay on BR and on 1257L.
| Monthly pay | 0T M1 | BR | 1257L |
|---|---|---|---|
| £1,500 | £300.00 | £300.00 | £90.20 |
| £2,000 | £400.00 | £400.00 | £190.20 |
| £3,000 | £600.00 | £600.00 | £390.20 |
| £6,000 | £1,771.66 | £1,200.00 | £1,352.06 |
Up to about £3,141 a month, 0T and BR take the same amount. Above it, 0T charges the higher rate on the excess, so it costs more than BR on large monthly pay. Compared with 1257L, the gap on ordinary pay is roughly the basic rate on £1,048.26, the free pay you would otherwise receive each month.
Getting off 0T
If your allowance is not used up, the code should not stay. Give the new employer the P45 from your previous job; GOV.UK's page on the P45 says HMRC should then correct the code after your first pay. Without a P45, fill in the starter checklist. HMRC can take up to 35 days from your start date to receive your details and send a new code, so wait that long before chasing.
After that, sign in to your HMRC online account and check that your employments, pensions and estimated pay are complete. When the new code reaches a cumulative payroll, the allowance from 6 April that you missed is given back through lower tax on the next payslip. While the code still ends in W1, M1 or X, that catch-up does not happen; the emergency tax calculator shows how much should come back once it changes.
S0T and C0T
The prefix only changes the bands. S0T runs pay through the six Scottish rates starting at the starter rate of 19%, while C0T uses the Welsh rates, which match those of England for 2026 to 2027. The reasons for the code are the same in all three nations, and so is the way out: complete records with HMRC.
One contrast is worth knowing. HMRC's payroll specification says there is a single emergency code for the whole of the UK, so the S and C prefixes are never added to it. A zero-allowance code, by contrast, does carry the prefix. If you live in Scotland and see 0T without the S, your address on HMRC's record may be out of date, which is worth checking at the same time as the code.