S1257L Tax Code: What the S Means and When It's Wrong

S1257L is the standard tax code for a Scottish taxpayer. The 1257L part means you get the full Personal Allowance of £12,570 tax-free, and the S prefix tells your employer or pension provider to apply Scottish income tax rates rather than the rates used in England, Wales and Northern Ireland. It is not an emergency code and it does not mean anything has gone wrong — but if you no longer live in Scotland, it means you are being taxed on the wrong scale.

• The S prefix is decided by where you live, not where your employer is based or where you work.
• 1257L gives £12,570 of tax-free pay, spread evenly across the year (£1,047.50 a month or £241.73 a week).
• Scotland has six income tax bands in 2026/27, from a 19% starter rate to a 48% top rate.
• Scottish rates only apply to non-savings, non-dividend income. Savings interest and dividends are taxed at UK-wide rates.
• A wrong S prefix is usually an out-of-date address on HMRC's records, and overpaid tax can normally be reclaimed for up to four years.

What the S in S1257L actually means

Since 2017 the Scottish Parliament has set the rates and bands of income tax on earnings, pensions, rental profits and self-employment profits for people who live in Scotland. HMRC identifies those people by putting an S in front of their PAYE tax code. Wales works the same way with a C prefix, although Welsh rates are currently identical to those in England and Northern Ireland, so a C code changes nothing in practice. An S code genuinely does change the arithmetic.

Break the code down:

• S — Scottish rates apply to this income.
• 1257 — your tax-free allowance for the year, with the last digit dropped. 1257 means £12,570.
• L — you are entitled to the standard Personal Allowance with no unusual adjustments.

So S1257L and 1257L give you exactly the same tax-free pay. The only difference is the set of rates applied to everything above it. Your employer does not choose the prefix. It comes from HMRC on a coding notice (a P6 or P9), based on the address HMRC holds for you.

Other Scottish tax codes you might see

If you have a second job or a pension alongside a salary, the second source of income often gets a flat-rate code instead. The Scottish versions all start with S:

If you see W1, M1 or X after S1257L, the code is being operated on a non-cumulative basis. That is common in a new job and usually corrects itself once HMRC issues a cumulative code, but it can leave you temporarily overpaid.

Who counts as a Scottish taxpayer

Scottish taxpayer status is about your main home, not your employer's registered office and not where your work is carried out. You are a Scottish taxpayer for a tax year if you are UK resident for tax and your only or main place of residence is in Scotland for more of that year than in any other part of the UK.

Some practical consequences of that rule:

• Living in Berwick-upon-Tweed and commuting to Edinburgh every day does not make you a Scottish taxpayer.
• Living in Glasgow and working remotely for a London company does make you one.
• Status applies to the whole tax year. You cannot be a Scottish taxpayer for part of it, so if you move mid-year HMRC looks at where your main home was for the greater part of the year.
• If you have homes in two parts of the UK, the main residence is the one with the closer connection — where your family lives, where you are registered with a GP, where you are on the electoral roll.
• Members of Parliament for Scottish constituencies and certain others are treated as Scottish taxpayers regardless of where they live.

Because status follows your address, it is your responsibility to tell HMRC when you move. The department does not automatically find out from your employer, your council or your bank.

Scottish bands on a payslip in 2026/27

Here is how income above the £12,570 Personal Allowance is taxed for someone with an S code, against the rates used elsewhere in the UK.

The crossover point sits at roughly £33,500. Below that, an S code produces a slightly smaller tax bill than a non-S code, because the 19% starter rate saves up to £39.67 a year. Above it, the 21% intermediate rate cancels that saving out, and from £43,663 the gap widens sharply.

Worked example: £50,000 salary with an S1257L code

Take a Scottish taxpayer earning £50,000 with no other income and no adjustments. Taxable income after the Personal Allowance is £37,430.

The same salary on a 1257L code in England would be taxed entirely at 20%: £37,430 × 20% = £7,486. The S prefix therefore costs £1,496.05 a year, or about £125 a month in take-home pay. National Insurance is identical either way — 8% on earnings between £12,570 and £50,270, so £2,994.40 in both cases.

The 50% marginal band

National Insurance is not devolved, so the Class 1 main rate of 8% still runs up to £50,270 while the Scottish higher rate starts at £43,663. Between those two figures a Scottish employee pays 42% income tax plus 8% NI on each extra pound — a 50% marginal rate on overtime, bonuses and pay rises. It drops back to 44% once earnings pass £50,270 and NI falls to 2%.

There is a second pinch point between £100,000 and £125,140, where the Personal Allowance is withdrawn at £1 for every £2 of income. A Scottish taxpayer in that range loses 45p in tax on the pound plus another 45p on the allowance being clawed back — an effective 67.5% marginal rate, against 60% elsewhere in the UK.

What the S code does not affect

Scottish rates apply only to non-savings, non-dividend income. Bank interest, dividends and capital gains are taxed at UK-wide rates wherever you live, so the Personal Savings Allowance of £1,000 for basic-rate taxpayers, the £500 dividend allowance and the £3,000 Capital Gains Tax exemption all work the same way. One quirk: for savings interest, HMRC uses the UK bands to decide which Personal Savings Allowance you get, so a Scottish higher-rate taxpayer earning between £43,663 and £50,270 still keeps the full £1,000. Our comparison of Scottish and English income tax goes through the differences in more detail.

When you have been wrongly given an S code

The most common reason for a wrong S prefix is a stale address. If you moved from Scotland to England and never updated HMRC, your code stays on the Scottish scale and you carry on paying Scottish rates. It works in the other direction too: people who move to Scotland sometimes keep a plain 1257L code and underpay, which produces a bill later.

Signs worth checking:

• Your payslip shows an S code but your home address is outside Scotland.
• Your take-home pay changed without any change to your salary or pension.
• You have a Scottish employer but live elsewhere, or vice versa — the prefix should follow your home, not the payroll.
• You moved during the year and your code switched mid-year when your main residence for the year as a whole did not.

How to get it corrected

Your employer cannot change the prefix on request. They must operate the code HMRC sends them until HMRC sends a replacement. The fix is to update your address with HMRC directly, through your Personal Tax Account on GOV.UK, or by contacting HMRC and telling them the date you moved. A new coding notice is then issued to your employer.

If the correction happens during the tax year and your new code is cumulative, payroll recalculates your tax from 6 April and any overpayment usually comes back in your next pay packet. If the year has already ended, HMRC normally reconciles it automatically and sends a P800 calculation with a refund. You can generally reclaim overpaid tax for up to four years after the end of the tax year concerned, so an S code that has been wrong since 2022/23 is still worth raising.

Before you contact anyone, it is worth running the code through our tax code checker to confirm that the number as well as the prefix is right. A code such as S1185L or S1257L with a K in front points to a benefit in kind, underpaid tax being collected, or an allowance HMRC has not applied.

What to do next

If your code is S1257L and you do live in Scotland, the code itself is almost certainly fine — the thing to sanity-check is the take-home figure. Put your salary into the Scotland tax calculator to see the six bands applied to your actual income, and compare it against the net pay on your payslip. If the two do not line up, or if the S should not be there at all, the tax code checker will show you which part of the code is out of step and what a corrected one would look like.