Transfer the allowance
Best£4,234Total tax for the couple
- Lower earner's tax
- £0
- Higher earner's tax
- £4,234
£1,260 of allowance moves across, giving the recipient a credit of up to £252.
Should we claim Marriage Allowance?
Works out whether transferring part of one personal allowance to the other partner saves tax, what it is worth, and how much four backdated years would add.
On the figures so far
Claiming saves £252 a year, and £1,008 more from the 4 backdated years.
The gap is £252 — wide enough to be real, and one figure was assumed. To be surer: whether you met the conditions in each of the earlier years — income and marital status both have to have been right at the time.
Refine it in 4 questions below.
The decision
Claiming saves £252 a year, and £1,008 more from the 4 backdated years.
£252 better than do not claim, on the same figures.
- £1,260Transferable
- £252A year
- £1,008Backdated
Why
- The lower earner has £4,570 of personal allowance going unused.
- Transferring £1,260 of it gives the higher earner a credit worth £252.
- Backdating 4 years adds £1,008 — the reason a first claim is usually worth several times the annual figure.
- Once claimed it renews automatically each year until you cancel it or stop qualifying.
Does this apply to you?
Each of these has to be true. Where your answers settle it we have said so; where they cannot, the test is yours to check.
You are married or in a civil partnership. — we cannot tell from your answers
ITA 2007 s. 55A
One of you has income below the personal allowance. — met, on your answers
ITA 2007 s. 55B
The other is a basic-rate taxpayer. — met, on your answers
ITA 2007 s. 55B(2)
Neither of you was born before 6 April 1935. — we cannot tell from your answers
ITA 2007 s. 45
You were both UK resident for the years claimed. — we cannot tell from your answers
ITA 2007 s. 55B(1)(d)
What this does not model
- The rates used are this year's. A backdated claim is settled at the rates of the year it relates to, so the earlier years will differ slightly.
- It assumes both of you were married or in a civil partnership, and resident, throughout each year claimed.
- It does not model the Married Couple's Allowance, which is a different and more generous relief where one of you was born before 6 April 1935.
This is information, not tax or financial advice. It shows how the rules apply to the figures you entered — it does not know the rest of your circumstances. Worth checking with an accountant before you act.
Rates as at 6 April 2026 — the 2026/27 tax year.
What to keep
The figures above are only as good as what sits behind them. These are the records HMRC would ask for.
- Both National Insurance numbers — the claim cannot be made without the partner's.
- Income figures for each year claimed, for both of you.
- The date of marriage or civil partnership, if it falls inside a year being claimed.
- P60s or tax calculations for the backdated years.
The dates that matter
| When | What | If you miss it |
|---|---|---|
| 5 April, four years after the tax year | Backdate a claim for an earlier year. | That year is out of time permanently. The backdated years are usually worth four times the current year, so this is the deadline that matters. |
| Any time in the current year | Make the claim. It applies to the whole tax year, not from the date of claiming. | Nothing, within the year — but leaving it means an unnecessary wait for the money. |
| As soon as circumstances change | Cancel if you separate, or if the recipient's income moves above the basic rate. | The claim renews automatically, and an ineligible year has to be paid back. |
How to actually do it
Work out which of you transfers
The one with the lower income gives up part of their allowance. Applying the wrong way round is the most common mistake, and HMRC's form asks the non-taxpayer to apply.
Apply online
The lower earner applies, through their Personal Tax Account or the Marriage Allowance service. You need both National Insurance numbers and some ID.
Ask for the earlier years in the same application
There is a box for backdating. Four tax years, each settled at that year's rates — usually the larger half of the money, and easily missed.
Check how it arrives
For the current year the recipient's tax code changes. Earlier years come as a cheque or a bank payment, and can take a couple of months.
Remember it renews
It carries on automatically until cancelled. If the recipient gets a pay rise into the higher rate, cancel it — otherwise the year has to be paid back.
Worked examples
Three situations, worked through. They use the same rules as the tool above, so you can check the arithmetic against a case near your own.
One partner £8,000, the other £35,000
- Allowance transferred
- £1,260
- Credit to the recipient
- £252
- Cost to the transferor
- Nil — their allowance was unused
- Four backdated years
- About £1,000 more
The textbook case: an unused allowance turned into cash. Backdating is where most of the money is.
One partner £13,500, the other £35,000
- Allowance transferred
- £1,260
- Extra tax for the transferor
- £186
- Credit to the recipient
- £252
- Net gain
- £66
Still positive, but much smaller: the transferor is now a taxpayer, so part of the allowance given up costs them tax. It is worth doing, and worth checking rather than assuming.
One partner £8,000, the other £54,000
- Recipient's rate
- Higher rate
- Allowance transferred
- None — disqualified
- Gain
- Nil
- Earlier years
- Still worth checking
A single pound above the basic-rate threshold removes the whole claim. But if their income was lower in an earlier year, that year is still claimable.
The rules behind this
Every figure above comes from one of these. Where we have interpreted rather than calculated, the tool says so.
A spouse or civil partner may transfer 10% of the personal allowance, rounded up to the nearest £10.
The recipient receives a tax reduction at the basic rate, not additional allowance.
The claim is not available if the recipient is liable above the basic rate.
A claim may be made up to four years after the end of the tax year.
The Married Couple's Allowance applies instead where either was born before 6 April 1935.
Questions people ask
How much is Marriage Allowance worth?
Up to £252 a year at current rates, and the claim backdates four years — so a first claim is often worth over £1,200. It is among the most commonly missed reliefs in the UK, with well over a million eligible couples not claiming.
Which of us applies?
The one with the lower income, because they are the one giving up part of their allowance. Applying the other way round is rejected.
What if the higher earner is just over the threshold?
No claim for that year — it is a cliff edge with no taper. A pension contribution that brings their income back under the basic-rate limit restores the claim as well as the relief, which is often worth doing for both reasons together.
Do we have to claim it every year?
No, it renews automatically. That is a convenience and a risk: if the recipient's income rises above the basic rate, or you separate, the claim has to be cancelled or the year repaid.
Can I claim if my spouse has died?
Yes. A claim can be made for years in which you were both eligible, including after a bereavement, within the four-year window.
Software that files it for you
Partner linksIf you keep your own books, these are the packages that handle Self Assessment and Making Tax Digital.
FreeAgent
Free optionMTD ready
The freelancer and contractor favourite, free with some bank accounts.
- Free forever with a NatWest, Royal Bank of Scotland, Ulster or Mettle business account
- Built-in Self Assessment and MTD for Income Tax filing
From £0 with a NatWest, RBS or Mettle account, otherwise about £19/mo
See FreeAgentQuickBooks
MTD ready
The big all-rounder with the deepest MTD track record.
- Sole Trader plan built specifically for Self Assessment and MTD
- Snap and store receipts, automatic bank feeds
From about £10/mo, frequent 90% off intro offers
See QuickBooksXero
MTD ready
The scale-up choice once you have staff, stock or VAT.
- Huge app marketplace and the accountant industry standard
- Strong for VAT, payroll and multi-user limited companies
From about £15/mo
See XeroWe may earn a commission if you sign up through one of these links. It never changes what we calculate, what we recommend, or the order they appear in.