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UK Tax Tools

Tax Code 1383M Explained

Marriage Allowance recipient — your Personal Allowance is £13,830, lifted by £1,260 from your lower-earning spouse's Marriage Allowance transfer.

At a glance — 1383M

Personal Allowance
£13,830
Region
UK-wide (rUK / Wales)
Cumulative?
Yes
Code type
Marriage Allowance

What does 1383M mean?

You have received a transfer of 10% of your partner's Personal Allowance through the Marriage Allowance scheme.

Your tax-free Personal Allowance is £13,830.

How much tax will you pay on 1383M?

Annual income tax HMRC would deduct on 2025-26 rates for a range of salaries, assuming the full year on this code. National Insurance is additional and the same across the UK.

Annual salary England / Wales / NI — income tax Effective rate Take-home (pre-NI)
£20,000 £1,234 6.2% £18,766
£30,000 £3,234 10.8% £26,766
£50,000 £7,234 14.5% £42,766
£80,000 £18,928 23.7% £61,072
£100,000 £26,928 26.9% £73,072

For Scottish / rUK side-by-side, or to model your own salary, student loan and pension contributions, use the tax code checker.

What you'll actually pay vs the standard code

1383M compared with 1257L — the standard code most single-job employees with no adjustments are on — at the same salary, 2025-26 rates.

Annual salary 1383M tax 1257L tax Difference
£30,000 £3,234 £3,486 −£252
£50,000 £7,234 £7,486 −£252
£80,000 £18,928 £19,432 −£504

Should you be on tax code 1383M?

M-suffix codes show you are the recipient of Marriage Allowance. Only eligible if your spouse or civil partner is a basic-rate taxpayer (earning under £50,270) and the transferor is a non-taxpayer (under £12,570). See the Marriage Allowance calculator to check whether it is worth claiming or transferring.

How to fix it if 1383M is wrong

  1. Check your current code in the HMRC app, your Personal Tax Account, or your latest P2 coding notice or payslip.
  2. New job with no P45? Ask your employer for a Starter Checklist — completing it correctly is what moves you off a temporary code.
  3. Not sure what your P45 figures mean, or already overpaid? See the P45 box-by-box guide to decode what your employer reported, or run the tax refund estimator to check what you might be owed.
  4. If HMRC agrees your code was wrong, most in-year corrections refund automatically through payroll; larger over- or underpayments are settled via a P800 calculation after the tax year ends.

Related tax codes

Check your own code: enter any HMRC tax code into the free tax code checker — it decodes the letters and number, shows your Personal Allowance, and estimates your take-home using 2025-26 or 2026-27 rates.

For the full plain-English guide to every UK tax code letter, prefix and suffix, see UK Tax Codes Explained 2026-27.

Sources

Tax code rules from gov.uk/tax-codes. Income tax rates from HMRC. Effective tax figures computed live from central configuration — correct for 2025-26.

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