M tax code
Marriage Allowance recipient — you receive 10% of your partner's Personal Allowance.
What this code means in practice
This code does not include a standard Personal Allowance — tax is calculated at a flat rate or with no free pay.
If your partner earns less than £12,570 and you are a basic rate taxpayer, they can transfer up to £1,260 of their allowance to you, reducing your tax by up to £252/year.
Check your take-home pay
Enter code M in our tax code checker or model a full salary with our salary calculator. Compare the result with your payslip to spot overpayment early.
Related reading
Frequently asked questions
What does tax code M mean?
Marriage Allowance recipient — you receive 10% of your partner's Personal Allowance.
Is M an emergency tax code?
M is not flagged as an emergency code in our database, but you should still verify it matches your circumstances in HMRC's Personal Tax Account.
How do I change my tax code?
Update your employment details in your Personal Tax Account at gov.uk, give your employer a P45 when changing jobs, or call HMRC on 0300 200 3300. Your employer applies the new code once HMRC issues it.
TaxHelper provides general information based on published HMRC rates and guidance. It is not regulated financial or tax advice. For decisions involving significant sums, complex circumstances, or if you are unsure, speak to a qualified accountant or HMRC directly.