What does the tax code
1383M mean?
1383M means Marriage Allowance is running in your favour. Your partner gave up £1,260 of their allowance, you received it, and your tax bill falls by up to £252 a year.
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Get the detailed breakdown + free reclaim guide1383M is one of the few tax codes that is unambiguously good news. It means somebody else gave you part of their Personal Allowance. Your tax-free pay for 2026/27 is £13,830 instead of £12,570, because your husband, wife or civil partner transferred £1,260 of theirs to you under Marriage Allowance.
The M is the giveaway. It is the only suffix that means you are receiving, and its mirror image, N, sits on your partner's code to show they are the one giving.
- 1383M Tax Code
- The tax code of someone receiving Marriage Allowance in 2026/27. The M suffix means an allowance transfer has been made in your favour. The number 1383 is your own £12,570 plus the £1,260 transferred from your spouse or civil partner, giving £13,830 of tax-free pay.
Where 1383 comes from
The arithmetic is unusually clean for a tax code.
| Component | Amount |
|---|---|
| Your own Personal Allowance | £12,570 |
| Transferred from your partner | £1,260 |
| Your total tax-free amount | £13,830 |
| Code number (final digit dropped) | 1383 |
The £1,260 is not arbitrary. It is 10% of the standard Personal Allowance, rounded to the nearest £10, and HMRC states on its Marriage Allowance guidance that the transfer "lets you transfer £1,260 of your Personal Allowance to your husband, wife or civil partner" and that this "reduces their tax by up to £252 in the tax year".
That £252 is 20% of £1,260, and it is a ceiling rather than an estimate. You cannot receive more by earning more, and there is no version of the scheme that transfers a different amount.
Worked example: 1383M on a £35,000 salary
- Gross salary: £35,000
- Subtract the 1383M allowance: £35,000 minus £13,830 = £21,170 of taxable income
- All of it sits in the basic rate band, so it is taxed at 20%
- Income tax for the year: £4,234
- Monthly tax-free pay: £13,830 divided by 12 = £1,152.50
On the standard 1257L code the same salary produces £22,430 of taxable income and £4,486 of tax. The saving is £252 exactly, which is £21 a month. Income tax only, National Insurance excluded, estimates to confirm with HMRC.
That £252 does not change if you earn £20,000 or £48,000. As long as you remain a basic rate taxpayer, the saving is identical, because it is simply 20% of a fixed £1,260.
Who is allowed to have 1383M
Four conditions have to hold, and all of them are about the couple rather than about you alone.
You are married or in a civil partnership. Living together does not qualify, however long. There is no unmarried equivalent of this relief.
Your partner earns less than their Personal Allowance. HMRC's condition is that the lower earner's income is normally below £12,570. They must be giving up allowance they were not going to use.
Your own income is between £12,571 and £50,270. You have to be a basic rate taxpayer. Earn more and you are not eligible, which is the single most common reason a valid claim later becomes invalid.
Neither of you was born before 6 April 1935. Couples where one partner was born before that date have access to the older and generally more valuable Married Couple's Allowance instead, and cannot claim both.
Scottish taxpayers have a different upper test, because the eligibility boundary follows the Scottish bands rather than the £50,270 rUK threshold. If your code carries an S prefix, check the position against Scottish rates rather than these figures. Our S1257L page sets out the 2026/27 Scottish bands.
The trap: a pay rise can make 1383M wrong
This is the failure mode worth remembering, because nothing warns you about it.
Marriage Allowance renews automatically each year. Once a claim is in place, HMRC keeps applying it until somebody cancels it. That is convenient while you remain eligible and a problem the moment you do not.
If your income rises above £50,270 you stop being a basic rate taxpayer and the claim should end. If it does not, you carry on receiving relief you are not entitled to, and HMRC recovers it later. The same applies if the couple separates, if the marriage ends, or if the lower earner's income rises above their Personal Allowance so that they were using it after all.
None of these is detected instantly. Employers do not report marital status and HMRC does not reassess eligibility every payday. The responsibility to cancel sits with the couple, and the recovery lands as an underpayment in a future code.
What 1383M is not
It is not Married Couple's Allowance. These are two different reliefs with confusingly similar names. Married Couple's Allowance is the older one, available only where at least one partner was born before 6 April 1935, and it works as a reduction in your tax bill rather than an addition to your allowance. It is generally worth considerably more. You cannot hold both, so a couple who qualify for the older relief should not be on a Marriage Allowance code at all.
It is not a joint allowance. Nothing has been pooled. A fixed £1,260 moved from one person's record to another's, and both codes changed to reflect it. Your partner really is worse off by whatever that £1,260 was worth to them, which is the point of our 1131N page.
It is not doubled by earning more. The £252 is a hard ceiling, not a rate. There is no income at which the transfer becomes worth more.
It is not automatic. Somebody applied. If you are on 1383M and neither of you remembers claiming, that is worth verifying rather than enjoying, because an unrecognised claim is sometimes a sign that HMRC has matched the wrong records.
Why the code number might not be exactly 1383
1383M is the clean case: a standard allowance plus a standard transfer and nothing else. In practice, other adjustments sit alongside the transfer, so the M suffix can appear on all sorts of numbers.
A company car deduction of £2,000 against the same transfer gives £11,830 and a code of 1183M. A flat rate expense of £60 on top gives £13,890 and 1389M. The suffix tells you the transfer is running; the number tells you the net of everything. If your code carries an M but the number is not 1383, that is normal and the breakdown on your coding notice will explain the difference.
Checking, cancelling and backdating
To check it. Sign in to your Personal Tax Account at gov.uk/personal-tax-account and open "Check your Income Tax". The breakdown behind your code shows the transferred allowance as an addition. Your partner's code should show the matching deduction and carry an N suffix, normally 1131N.
To cancel it. Contact HMRC through the Marriage Allowance service. The lower earner is the one who applied, and cancellation rules differ depending on whether the relationship has ended or circumstances have simply changed, so it is worth doing this properly rather than assuming it will lapse.
To backdate it. If you have only just claimed, earlier years may still be available. HMRC currently states that "you can backdate your claim to 6 April 2022 (the 2022 to 2023 tax year) for any years you were eligible". At up to £252 a year, a full backdated claim across 2022/23 to 2026/27 is worth as much as £1,260 in total, paid separately from your code. Our guide to reclaiming overpaid tax covers how closed years are settled.
To sanity check what your code should be, our free tax code checker will estimate it from your circumstances. It is an estimate for taking to HMRC, not advice.
People also ask
- 1383M gives £13,830 of tax-free pay: your own £12,570 plus £1,260 transferred by your partner
- The M suffix means you are the recipient, and your partner should carry the matching N suffix
- It is worth up to £252 a year, which is 20% of £1,260 and a ceiling rather than an estimate
- You must be a basic rate taxpayer, and your partner must be earning below their Personal Allowance
- The claim renews automatically, so a pay rise above £50,270 makes it wrong until someone cancels it
- Unclaimed relief can be backdated to 6 April 2022, worth up to £1,260 across five tax years
- Couples where one partner was born before 6 April 1935 should look at Married Couple's Allowance instead
Related tax codes: 1131N tax code | M tax code | N tax code | 1257L tax code | How to check your tax code
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