What Is a Married Man’s Tax Code? 1257L and Marriage Allowance

In the UK, a married man’s tax code is almost always 1257L, the same code used by most employees whether they’re single, married, or in a civil partnership. Getting married does not change your tax code on its own. The code only shifts if you or your spouse actively claim Marriage Allowance, which adds an M suffix to the recipient’s code and an N suffix to the transferor’s, moving £1,260 of Personal Allowance between you and saving the household up to £252 a year.

Why 1257L Is the Default

Your PAYE tax code tells your employer how much income tax to withhold before your pay reaches your account.¹ For the 2025/26 tax year, 1257L is the most common code, applied to people with one job, no untaxed income, and no taxable benefits like a company car.²

The number is your tax-free Personal Allowance divided by ten. 1257 means £12,570 of income each year before any tax is due. The letter L means you get the standard Personal Allowance with no special adjustments.³

HMRC treats every person as an independent taxpayer. Your spouse’s income has no bearing on your code, and marriage itself triggers no automatic adjustment. If your payslip still shows 1257L after the wedding, that’s normal.

When Marriage Does Change Your Code

Marriage Allowance is the one situation where being married directly rewrites your tax code. It lets a lower-earning spouse hand £1,260 of their Personal Allowance to their partner, cutting the recipient’s tax bill by up to £252 for the year.⁴ The rule sits in Part 3, Chapter 3A of the Income Tax Act 2007.⁵

Once the transfer is in place, the codes change on both sides:

The receiving partner gets an M suffix. The number rises from 1257 to 1383, reflecting a tax-free amount of £13,830.
The transferring partner gets an N suffix. The number drops from 1257 to 1131, reducing their tax-free amount to £11,310.³

The saving works because the transferred £1,260 is sheltered from the 20% basic rate. For the transferor, giving up part of the allowance costs nothing so long as their income is already below £12,570; they weren’t going to use that slice anyway.

Who Qualifies

Three conditions all need to be met:

You’re married or in a civil partnership. Cohabiting couples cannot claim, regardless of how long they’ve lived together.⁶
The transferor earns below £12,570, so they’re not paying income tax.
The recipient is a basic-rate taxpayer. In England, Wales, and Northern Ireland that means income between £12,571 and £50,270. In Scotland the recipient must pay the starter, basic, or intermediate rate, generally income between £12,571 and £43,662.⁴

If the higher earner tips into higher-rate or additional-rate territory, eligibility ends. A pay rise or bonus can quietly push a couple out of qualifying without either partner noticing.

Backdating

You can backdate a Marriage Allowance claim up to four tax years, provided you were eligible in each of those years.⁶ At £252 a year, a full backdate plus the current year can return over £1,000 as a lump sum. If you’ve been married for years and never claimed, it’s worth checking.

Scottish and Welsh Codes

If you live in Scotland, your code carries an S prefix (for example, S1257L). Welsh residents get a C prefix. Those prefixes tell your employer to apply Scottish or Welsh income tax rates.³ Marriage Allowance still applies, though the Scottish eligibility bands are narrower as noted above. The £1,260 transfer and £252 maximum saving are the same across the UK.

A Different Allowance for Older Couples

There’s a separate, more generous relief called Married Couple’s Allowance, available only when at least one spouse was born before 6 April 1935. It’s not the same as Marriage Allowance, and you can’t claim both. For 2026/27 it’s worth up to £1,170 off your tax bill, with a minimum of £453 regardless of income. If you or your spouse meets the age condition, this is the one to look at.

Other Codes You Might See

Plenty of tax codes have nothing to do with marriage. If yours isn’t 1257L or one of the marriage suffixes, one of the following usually explains it:

K at the start means your untaxed income (a company car, a state pension, other perks) is greater than your Personal Allowance, so your employer adds the excess to your taxable pay.³
BR taxes all income from that job or pension at the basic rate, typical for a second job where the allowance is already used at your main employment.
0T means your Personal Allowance is spent or your employer lacks the details to apply the right code, often at the start of a new job.
D0 or D1 taxes all income from that source at higher or additional rate, again usually a second income.
W1 or M1 are emergency codes calculated pay period by pay period rather than cumulatively, and should be corrected once HMRC updates your record.³

If the number on your payslip doesn’t match what you’d expect from your allowance and benefits, that’s a signal to log in and check.

How to Apply

The lower-earning spouse makes the application, because they’re the one giving up part of their allowance. You’ll need both National Insurance numbers, the date of your marriage or civil partnership, and an estimate of both partners’ annual income.⁶

The fastest route is the online application at GOV.UK.⁷ You can also call the Marriage Allowance line on 0300 200 3300 (Monday to Friday, 8am to 6pm), or complete the paper MATCF form and post it. Once processed, HMRC issues a P2 Notice of Coding to both partners and updates each employer’s payroll. Monthly-paid employees should see the new code on the next payslip or the one after; weekly-paid staff usually see it within three pay periods.⁸

When Circumstances Change

Marriage Allowance doesn’t look after itself indefinitely.

Divorce or Separation

You must cancel if you divorce, dissolve a civil partnership, or legally separate. The cancellation can be backdated to 6 April. Either partner can cancel.⁹

Death of a Spouse

If you transferred allowance to a partner who then dies, your Personal Allowance returns to normal and their estate keeps the increased allowance for that tax year. If your partner transferred to you and dies, you keep the higher allowance until 5 April.⁹

Income Changes

If the higher earner moves above £50,270 (or £43,662 in Scotland), the couple loses eligibility. If the lower earner moves above £12,570, they’re now a taxpayer and the transfer stops making sense. HMRC won’t necessarily spot these shifts mid-year, so review the arrangement each April.

Cancelling

The person who made the claim is the one who cancels, unless the relationship has ended, in which case either can. Leaving the Marriage Allowance section blank on a Self Assessment return does not cancel it; you have to cancel separately online or by calling 0300 200 3300.⁹

Checking Your Code

Your HMRC personal tax account shows your current code, the allowances and deductions used to build it, and your estimated income for the year.¹⁰ The HMRC app does the same. If something looks wrong, you can update your income details there.

Where you’ve been on the wrong code and overpaid, HMRC will normally tell your employer to refund the difference through payroll once the code is fixed. After the tax year ends, HMRC reconciles your record against what your employer reported and writes to you if there’s a shortfall or overpayment. Refunds for overpayment are usually processed automatically, though the timing depends on when HMRC has the full picture.⁸

1
GOV.UK. Income Tax – How You Pay Income Tax
2
GOV.UK. Understanding Your Employees’ Tax Codes
3
GOV.UK. What Your Tax Code Means
4
GOV.UK. Marriage Allowance – How It Works
5
The National Archives. Income Tax Act 2007 – Part 3, Chapter 3A
6
HM Revenue and Customs. Marriage Allowance Transfer
7
GOV.UK. Apply for Marriage Allowance Online
8
GOV.UK. Tax Codes – If You’ve Paid Too Much or Too Little Tax
9
GOV.UK. Marriage Allowance – If Your Circumstances Change
10
GOV.UK. Check Your Income Tax for the Current Year