Updated for the 2026/27 tax year
The SD1 tax code
All your income from this job or pension is taxed at the higher rate in Scotland
What it does to your pay
SD1 charges 42% on everything from this job or pension — the Higher rate for Scotland. There is no tax-free amount and there are no band steps: the whole payment is taxed at that one rate, from the first pound.
Codes like this are normally used on a second job or a second pension, where your allowance is already being used up by the first one. If it is on your ONLY income, that is the case worth querying — you may be paying tax on an allowance you are entitled to.
Source: Reg 7(3)(bb) with reg 32B — see SD0.
A worked example
On pay of £30,000 for the year, SD1 makes £30,000 taxable and produces £12,600 of income tax. The standard code on the same pay would produce £3,451.07, so this code costs £9,148.93 more over the year.
- £30,000 at 42% = £12,600
Income tax only — National Insurance, student loan repayments and pension contributions are separate and are not included here.
How SD1 is written on a payslip
SD1 is the code. Anything printed after it is a marker, and the markers this site recognises are W1, M1, X and NONCUM — HMRC’s payroll names for the non-cumulative basis, which the regulations set out at regs 26–31 and which the emergency-code page explains in full. Whether a marker changes anything for THIS code is a question for the regulation quoted above, not for the marker.
The space is optional and payslips print it both ways. SD1 W1 and SD1W1 are the same string as far as this site is concerned: the checker upper-cases what you type and strips the spaces out before it looks the code up, so either spelling reaches this page.
Is it right for you?
Check whether this is your only income. A flat-rate code on a sole job means your Personal Allowance is not being applied anywhere, which is usually wrong and usually recoverable.
Whatever the answer, the code HMRC holds for you is the one that governs, and it is on your Personal Tax Account. If your tax code is wrong sets out how to get it changed.
Common questions
What does the SD1 tax code mean?
All your income from this job or pension is taxed at the higher rate in Scotland. It charges 42% on the whole payment with no tax-free amount and no band steps.
How much tax does SD1 take on £30,000 a year?
On pay of £30,000 for the year, SD1 makes £30,000 taxable and produces £12,600 of income tax. The standard code on the same pay would produce £3,451.07, a difference of £9,148.93 over the year. Income tax only — National Insurance, student loan repayments and pension contributions are separate and are not included.
Is SD1W1 the same code as SD1?
Yes. W1, M1, X and NONCUM are the markers HMRC uses for the non-cumulative basis, and a marker after SD1 leaves the code itself unchanged. The space is optional: this site's checker reads SD1W1 and SD1 W1 identically, because it strips spaces before looking the code up.
Independent tool not affiliated with HMRC. For your official code, log in to your Personal Tax Account. Check your tax code on GOV.UK.
Letters and law are not the same thing. The PAYE Regulations create these codes by describing what they DO — “the basic rate code”, “the nil tax code” — and, with one exception, never write down the letters HMRC prints on your payslip. The letters are HMRC’s naming for those functions. This site labels which is which on every page, and the sources page shows the search behind that statement.
The figures and rules on this site are taken from the Income Tax (Pay As You Earn) Regulations 2003, the Income Tax Act 2007 and HMRC’s published guidance, and are shown as they were found. They have not been signed off by a reviewer. Where the law and HMRC’s naming differ, the page says which is which rather than blending them. For anything that affects a decision, the cited document governs and this site does not.