Tax Code Calculator
Enter your income and the tax code from your payslip. We’ll translate the code into plain English, estimate the income tax it deducts, and compare it against the code we’d expect for your situation.
This tool gives a rough estimate of the income tax collected through PAYE under one code, for one job or pension. It does not model National Insurance, student loans, pension contributions, taxable benefits, savings or dividend income, and it assumes the code applies for the full year. It is general information, not tax advice — for a definitive answer, talk to TaxDigit. Rates verified against GOV.UK as at 12 July 2026.
What is a tax code?
A tax code is the short string of numbers and letters — 1257L, S1257L, BR, K497 — that HMRC issues so your employer or pension provider knows how much Income Tax to deduct through PAYE before your pay reaches your bank account. Every job and every pension you hold has its own code, and each one can be right or wrong independently.
Millions of codes are issued automatically every year, and they are only as good as the information HMRC holds about you. Change jobs, pick up a company benefit, start drawing a pension, and the code can lag behind reality — which is how people quietly overpay (or underpay) tax for years. The responsibility for checking the code sits with you, not your employer and not HMRC. If your tax code doesn’t look right, it usually isn’t.
You won’t have a tax code if you are fully self-employed with no PAYE income, unemployed, or receiving only the State Pension — in those cases tax is settled through Self Assessment instead.
Where to find your tax code
What the numbers mean
The numbers are your tax-free Personal Allowance with the last digit removed: multiply by ten. A code of 1257 means you can earn £12,570 in the year before Income Tax starts — the standard Personal Allowance for both 2025/26 and 2026/27 (frozen since April 2021, and now legislated to stay frozen until April 2031 following the Autumn Budget 2025).
HMRC adjusts the number for your circumstances. Taxable perks such as a company car, private medical insurance or an interest-free loan reduce it; claims such as working-from-home relief, professional subscriptions or the Marriage Allowance increase it. Earn over £100,000 and the allowance itself is withdrawn — £1 lost for every £2 above the line, gone entirely at £125,140 — so high earners see much smaller numbers, or none at all.
What the letters mean
The letters describe your situation. A prefix of S means you’re a Scottish taxpayer (S1257L); C means Welsh rates apply (C1257L). The suffix or stand-alone codes work like this in 2025/26 and 2026/27:
| Code | What it means |
|---|---|
| L | You get the standard tax-free Personal Allowance — £12,570 for most people earning under £100,000 with no taxable perks. |
| M | Marriage Allowance recipient — your spouse or civil partner has transferred £1,260 of their allowance to you (typically code 1383M), saving you up to £252 a year. |
| N | Marriage Allowance transferor — you’ve given £1,260 of your allowance to your partner (typically code 1131N). |
| T | You have a Personal Allowance set by the number shown, but HMRC needs to review the code — usually because your affairs are complex or the allowance is tapered. |
| 0T | No tax-free allowance at all; everything is taxed through the bands. Common when a new employer doesn’t have your details yet, or when income exceeds £125,140. |
| BR | All income from this job or pension taxed at the 20% basic rate with no allowance — normally used for a second job or pension. Make sure HMRC knows which job is your main one. |
| D0 | All income from this source taxed at the 40% higher rate — again usually a second income. (Scotland: SD0 taxes at the 21% intermediate rate.) |
| D1 | All income from this source taxed at the 45% additional rate. (Scotland: SD1 applies the 42% Scottish higher rate.) |
| SD2 / SD3 | Scotland only — all income from this source taxed at the 45% advanced rate (SD2) or the 48% top rate (SD3). |
| K | Your deductions exceed your allowance, so the number works in reverse: K497 adds roughly £4,970 of taxable income. Usually caused by taxable benefits or tax owed from an earlier year. PAYE can’t take more than half of your pay under a K code. |
| NT | No tax to be deducted from this income — rare, and worth double-checking. |
| W1 / M1 / X | Emergency codes, shown after the number (e.g. 1257L M1). Tax is worked out on that week or month alone rather than cumulatively — common when starting a new job. Fine short-term, expensive if it sticks. |
Income tax bands behind your code
Your code sets what’s tax-free; these bands set what happens to the rest. Figures verified against GOV.UK as at 12 July 2026.
England, Wales & N. Ireland — 2025/26 and 2026/27
| Band | Income | Rate |
|---|---|---|
| Personal Allowance | Up to £12,570 | 0% |
| Basic rate | £12,571 – £50,270 | 20% |
| Higher rate | £50,271 – £125,140 | 40% |
| Additional rate | Over £125,140 | 45% |
Thresholds are unchanged across both years. From 6 April 2026 dividend tax rates rose to 10.75% (basic) and 35.75% (higher) — if you take dividends, your code may change to collect this.
Scotland — 2026/27 (2025/26 in brackets)
| Band | Income | Rate |
|---|---|---|
| Starter | £12,571 – £16,537 (£15,397) | 19% |
| Basic | to £29,526 (£27,491) | 20% |
| Intermediate | to £43,662 | 21% |
| Higher | to £75,000 | 42% |
| Advanced | to £125,140 | 45% |
| Top | Over £125,140 | 48% |
Scottish rates apply to earnings and pensions; savings and dividends follow UK-wide rates.
Is your tax code wrong? The five situations to watch
HMRC repays billions of pounds of overpaid PAYE tax every year — and most of it starts with a wrong code. You’re most at risk if any of these apply:
| 1 | You changed jobs. If paperwork crosses over, HMRC may briefly think you hold two jobs at once and split or remove your allowance. |
| 2 | You have more than one income. Two jobs or a job plus a pension means two codes — and only one of them should carry your Personal Allowance. |
| 3 | You get workplace benefits. A company car, medical cover or other perks reduce your code — but the deduction should match the benefit you actually receive, and it often doesn’t. |
| 4 | You started work or a pension mid-year. New starters are routinely parked on emergency codes (1257L W1/M1/X) or 0T. Never assume the first few payslips are right. |
| 5 | You recently retired or drew on a pension. Multiple pensions plus the State Pension is the classic recipe for a wrong code — the State Pension is taxable but paid gross, so it’s collected through the code on your other income. |
Overpaid? How to get your money back
If the current year’s code is wrong, ask HMRC to fix it — the correction and any refund then flow automatically through your next payslips. For earlier years, HMRC issues a P800 calculation letter (or a Simple Assessment) between June and the following March; you claim the refund online through your Personal Tax Account or the HMRC app, usually receiving it within days. You can go back up to four years, so claims made now can reach back to 2022/23 — but that door closes on 5 April each year, so don’t sit on it.
Underpaid? Don’t panic
Underpayments under £3,000 are normally collected painlessly by adjusting next year’s code rather than demanding a lump sum. If the underpayment arose because HMRC failed to act on information it already had, an extra-statutory concession (ESC A19) can sometimes cancel tax owed from earlier years — it’s not automatic and needs to be argued properly, which is exactly the kind of thing we do for clients.
Employers: wrong codes are your problem too
Every P45, starter checklist, P6 and P9 notice has to be applied correctly and on time — under RTI, mistakes surface fast and generate employee queries, HMRC correspondence and trust issues on payday. TaxDigit’s fully managed payroll service applies HMRC code notices automatically, runs your RTI submissions, and gives your team a straight answer when they ask “why has my tax gone up?”. Employees: if your employer runs payroll with us, your code worries are already handled — and if not, we can still review your position and deal with HMRC as your agent.
Tax code FAQs
What should my tax code be for 2026/27?
If you have one employer, no taxable perks and earn under £100,000, expect 1257L — S1257L in Scotland, C1257L in Wales. Anything else deserves a closer look with our checker above.
What does the 1257L tax code mean?
You receive the standard £12,570 Personal Allowance spread evenly across the year, with income above it taxed through the normal bands. It has been the default code since April 2021 and remains so for 2025/26 and 2026/27.
What is an emergency tax code?
Codes ending W1, M1 or X tax each payday in isolation instead of cumulatively, so you get just one week’s or month’s slice of allowance. They’re a stop-gap while HMRC catches up with a change — if one persists past a couple of paydays, chase it, because refunds don’t flow automatically under an emergency code.
Why is there a K at the start of my code?
A K code means your taxable deductions — company benefits, state pension, or tax owed from earlier years — exceed your Personal Allowance, so the code adds taxable income instead of sheltering it. K497 adds roughly £4,970 a year. K codes are error-prone and always worth verifying.
How do I check my tax code is correct?
Compare the code on your payslip against your circumstances using the calculator on this page, then check the detail in your HMRC Personal Tax Account or the HMRC app, which shows exactly how the code was built. If something doesn’t match — a benefit you no longer get, a job you’ve left — that’s your flag.
How do I claim back overpaid tax?
For the current year, getting the code corrected releases the refund through your wages. For past years, respond to your P800 letter online, or make a claim yourself — you can go back four years, currently to 2022/23. TaxDigit can handle the whole claim as your agent, including chasing HMRC when it stalls.
Why has my tax code changed?
Codes change when HMRC learns something new: a benefit reported on a P11D, a second income, a State Pension starting, a Self Assessment balance being coded out, or a Marriage Allowance claim. The P2 coding notice explains the arithmetic — if any line looks stale or wrong, it probably is.
Do I have a tax code if I’m self-employed?
Not for your self-employment itself — that income is taxed through Self Assessment. But if you also have a PAYE job or a pension, that source still carries a code, and HMRC sometimes uses it to collect your Self Assessment tax too.
Does the Marriage Allowance change my tax code?
Yes — the recipient’s code gains a M suffix (typically 1383M) and the giver’s becomes N (typically 1131N), reflecting the £1,260 transfer. It’s worth up to £252 a year and can be backdated four years, but it only pays when one of you earns under the allowance and the other is a basic-rate taxpayer.
Can TaxDigit deal with HMRC about my code for me?
Yes. As chartered certified accountants and registered agents we can review your coding notices, correct errors with HMRC on your behalf, reclaim overpayments from earlier years, and challenge unfair underpayment demands under ESC A19. Start with a free conversation.
Think your tax code is wrong?
Send us your payslip and coding notice — we’ll tell you straight whether you’re owed money, and claim it back from HMRC if you are.