What does the 0T tax code mean?

The 0T tax code (zero T) tells your employer to give you no Personal Allowance - the "0" is literally £0 of tax-free income. Unlike BR (flat 20% everywhere), 0T then runs your pay through the full UK tax band structure: 20% up to £37,700, 40% up to £125,140, 45% above. So a higher-earning new starter on 0T gets hit with 40% tax from pound one, not the smoother basic-rate-only treatment a BR code would give.

Why has HMRC put me on 0T?

Three common reasons: (1) you started a new job without submitting a P45 or completing a Starter Checklist, and your new employer defaulted to 0T while waiting for HMRC instructions; (2) your income exceeds £125,140, so your PA has been fully tapered to zero (£1 of PA is removed for every £2 of income above £100,000, reaching zero at £125,140); (3) HMRC explicitly removed your PA for a specific reason such as failure to respond to correspondence or recovery of significant tax debt.

How is 0T different from BR?

BR caps everything at 20%. 0T applies the full band structure with no PA. For a £25,000 second job the two codes give identical Income Tax (£5,000 either way) - both fall entirely within the 20% basic-rate band. For a £60,000 second job, BR collects £12,000 (20% of everything) while 0T collects £15,440 (£7,540 at 20% plus £8,892 at 40%). HMRC chooses 0T over BR when the second source is large enough that BR alone would leave a sizeable year-end under-payment.

Will I get a refund from a 0T code?

Yes, if 0T was applied while your PA was actually unused. Once HMRC receives your P45 or Starter Checklist they will switch you to 1257L cumulative; the next payslip recalculates year-to-date and refunds the over-paid tax automatically. You do not need to file Self Assessment to recover this. For pension flexible-drawdown over-payments (where HMRC routinely applies 0T or M1 on the first payment) file form P55, P53Z or P50Z and HMRC refunds within around 30 days.

Is 0T the same as 0T W1 or 0T M1?

Close but not identical. Plain 0T is cumulative - your year-to-date taxable pay is tracked across pay periods. 0T W1 (weekly) or 0T M1 (monthly) is non-cumulative emergency-style: each pay period is taxed in isolation, with 1/52 or 1/12 of the band thresholds applied per period. The total tax for the year tends to be similar; the cash-flow timing differs.

Does the 0T code apply in Scotland?

Yes - Scottish taxpayers see S0T. The mechanism is identical (no PA), but the bands above are Scottish: 19% on the first £3,967, 20% to £16,956, 21% to £31,092, 42% to £62,430, 45% to £112,570, then 48% above. A Scottish higher-earner on S0T can therefore be paying 42-48% from a low income level, which is more punitive than the rest-of-UK 0T equivalent.

0T Tax Code Explained (2026/27)

0T (zero T) gives you no Personal Allowance and runs every pound of your pay through the full UK tax band structure: 20% basic, 40% higher, 45% additional. It is stricter than BR (which caps everything at 20%) and is HMRC's standard response when your PA is fully used elsewhere, fully tapered to zero, or temporarily unknown at a new employer.

How to read the 0T code

0 = zero Personal Allowance (£0 ÷ 10 = 0).
T = HMRC has applied a non-standard adjustment; the code may be temporary.
S0T = Scottish 0T (Scottish bands above).
C0T = Welsh 0T (currently same rates as rest-of-UK).
0T W1 / 0T M1 / 0T X = non-cumulative variant - each pay period taxed in isolation.

Note the letter is a capital "T" - some payslip systems print it as "OT" with a capital "O" which makes it visually identical to a zero. Either way the mechanics are the same: no allowance, full bands.

Worked example: £40,000 on 0T vs 1257L

This is the classic mid-range case - someone earning £40,000 who started a new job without a P45 and was put on 0T. England/NI rest-of-UK, no pension, no student loan:

Line	0T annual	1257L annual
Gross salary	£40,000	£40,000
Personal Allowance applied	£0	£12,570
Tax at 20% basic rate	£7,540	£5,486
Tax at 40% higher rate	£920	£0
Total Income Tax	£8,460	£5,486
Class 1 NI	£2,194	£2,194
Take-home	£29,346	£32,320

The 0T code over-collects £2,974 of Income Tax compared with a normal 1257L code on this salary. That money is fully recoverable - either automatically when HMRC switches you to 1257L (the next payslip refunds the year-to-date excess), or via a P800 reconciliation in the summer after the tax year ends.

0T at different income levels

Gross	Income Tax (0T)	NI	Take-home
£15,000	£3,000	£194	£11,806
£25,000	£5,000	£994	£19,006
£35,000	£7,000	£1,794	£26,206
£50,000	£12,460	£2,994	£34,546
£70,000	£20,460	£3,411	£46,129
£100,000	£32,460	£4,011	£63,529
£125,140	£42,516	£4,513	£78,111
£150,000	£53,703	£5,011	£91,286

How to check if 0T is right for you

0T is correct in three narrow cases:

Your total income exceeds £125,140, so the PA has been fully tapered to zero by HMRC.
You have a large second income source where BR would materially under-collect (typical: a second job above £40,000 alongside a main job already in higher-rate territory).
HMRC has deliberately withdrawn your PA - usually after extended failure to respond to PAYE coding notices.

Otherwise 0T is wrong, and you are being over-taxed. Verify via your Personal Tax Account - it shows the precise reason HMRC assigned the code and which income sources they expect to use the PA.

How to fix a wrong 0T code

Hand your new employer a P45 from the previous job (or complete the Starter Checklist correctly - tick Statement A if this is your only job since 6 April).
Use the GOV.UK app or Personal Tax Account to update HMRC's record of your employment.
Online via gov.uk/tax-codes/if-your-tax-code-is-wrong.
Phone HMRC PAYE on 0300 200 3300 (Mon-Fri 8am-6pm) - they can issue the corrected code to your employer the same day.
For pension flexible-drawdown over-tax, file P55 (more pension to take), P53Z (fully drawn, still working) or P50Z (fully drawn, not working) - HMRC refunds within around 30 days rather than waiting for year-end.

Related tax codes

Frequently asked questions about 0T

What does the 0T tax code mean?: The 0T tax code (zero T) tells your employer to give you no Personal Allowance - the "0" is literally £0 of tax-free income. Unlike BR (flat 20% everywhere), 0T then runs your pay through the full UK tax band structure: 20% up to £37,700, 40% up to £125,140, 45% above. So a higher-earning new starter on 0T gets hit with 40% tax from pound one, not the smoother basic-rate-only treatment a BR code would give.
Why has HMRC put me on 0T?: Three common reasons: (1) you started a new job without submitting a P45 or completing a Starter Checklist, and your new employer defaulted to 0T while waiting for HMRC instructions; (2) your income exceeds £125,140, so your PA has been fully tapered to zero (£1 of PA is removed for every £2 of income above £100,000, reaching zero at £125,140); (3) HMRC explicitly removed your PA for a specific reason such as failure to respond to correspondence or recovery of significant tax debt.
How is 0T different from BR?: BR caps everything at 20%. 0T applies the full band structure with no PA. For a £25,000 second job the two codes give identical Income Tax (£5,000 either way) - both fall entirely within the 20% basic-rate band. For a £60,000 second job, BR collects £12,000 (20% of everything) while 0T collects £15,440 (£7,540 at 20% plus £8,892 at 40%). HMRC chooses 0T over BR when the second source is large enough that BR alone would leave a sizeable year-end under-payment.
Will I get a refund from a 0T code?: Yes, if 0T was applied while your PA was actually unused. Once HMRC receives your P45 or Starter Checklist they will switch you to 1257L cumulative; the next payslip recalculates year-to-date and refunds the over-paid tax automatically. You do not need to file Self Assessment to recover this. For pension flexible-drawdown over-payments (where HMRC routinely applies 0T or M1 on the first payment) file form P55, P53Z or P50Z and HMRC refunds within around 30 days.
Is 0T the same as 0T W1 or 0T M1?: Close but not identical. Plain 0T is cumulative - your year-to-date taxable pay is tracked across pay periods. 0T W1 (weekly) or 0T M1 (monthly) is non-cumulative emergency-style: each pay period is taxed in isolation, with 1/52 or 1/12 of the band thresholds applied per period. The total tax for the year tends to be similar; the cash-flow timing differs.
Does the 0T code apply in Scotland?: Yes - Scottish taxpayers see S0T. The mechanism is identical (no PA), but the bands above are Scottish: 19% on the first £3,967, 20% to £16,956, 21% to £31,092, 42% to £62,430, 45% to £112,570, then 48% above. A Scottish higher-earner on S0T can therefore be paying 42-48% from a low income level, which is more punitive than the rest-of-UK 0T equivalent.