How to Backdate Marriage Allowance Claims for Up to 4 Years

What Is Marriage Allowance?

Marriage Allowance is a government scheme that allows couples — who are married or in a civil partnership — to transfer a portion of one partner's Personal Allowance to the other. Specifically, the lower-earning partner can transfer up to 10% of their Personal Allowance to the higher-earning partner.

In 2026/27, the Personal Allowance is £12,570, so the transferable amount is £1,257. For the receiving partner, this increases their effective Personal Allowance from £12,570 to £13,827, reducing their tax bill by £251.40 (20% of £1,257), rounded up by HMRC to £252 per year.

The scheme was introduced in April 2015 and has been running continuously since. Despite over a decade of availability, HMRC estimates that millions of eligible couples have still not claimed — leaving significant amounts of money unclaimed.

Who Is Eligible?

The eligibility criteria are specific:

The Lower-Earning Partner Must:

• Have income below the Personal Allowance (under £12,570 in 2026/27) — or have no income at all
• Be a UK taxpayer (or non-taxpayer — having income below the threshold is fine)

The Higher-Earning Partner Must:

• Be a basic rate taxpayer — income between £12,571 and £50,270 in England, Wales, and Northern Ireland
• Not pay higher rate (40%) or additional rate (45%) tax in the relevant tax year
• Not be in receipt of the Married Couple's Allowance (a separate, older scheme for those born before 6 April 1935)

Note: The income limits are slightly different for Scotland due to the separate Scottish Income Tax bands.

Both Partners Must:

• Be married or in a civil partnership — cohabiting couples do not qualify
• Both be UK resident for tax purposes

The Value of Backdating

From the 2026/27 tax year, you can backdate Marriage Allowance claims to the earliest eligible year within the 4-year time limit. This means claims can currently be made for the following years:

The maximum lump sum from backdating four previous years (2022/23 to 2025/26) is £1,008, plus the current year saving of £252, for a combined benefit of up to £1,260 in the first year of claiming.

The backdated amounts are paid as a cash lump sum, separate from the ongoing year's allowance (which is applied via a tax code adjustment).

How to Make the Claim

The claim is made by the lower-earning partner (the one transferring their allowance). The higher-earning partner cannot initiate the claim. Here is the step-by-step process:

Step 1: Check Eligibility for Each Year

Before claiming, confirm that both partners met the eligibility criteria in each tax year you wish to backdate to. Key questions:

• Was the lower earner below £12,570 in that year?
• Was the higher earner paying basic rate tax (not higher rate) in that year?
• Were you married or in a civil partnership throughout that tax year?

Note: You must have been eligible throughout the entire tax year to claim for that year. If you married mid-year, you can still claim — Marriage Allowance is not pro-rated; the full year's allowance applies as long as you were married at some point during that tax year.

Step 2: Go to GOV.UK

Visit gov.uk/apply-marriage-allowance and click "Apply online." You will need your Government Gateway credentials for the lower-earning partner's HMRC account. If you do not have a Government Gateway account, you can create one during the process (you will need your National Insurance number).

Step 3: Complete the Online Form

The form asks for:

• Your National Insurance number
• Your partner's National Insurance number
• Confirmation that you meet the eligibility criteria
• Details of any prior claims

The online claim covers the current year and automatically asks if you want to backdate. Select yes and choose which prior years you wish to include.

The form takes approximately 10 minutes to complete.

Step 4: Alternatively, Claim by Phone or Post

If you prefer not to claim online:

• Phone: Call HMRC on 0300 200 3300. Lines are open Monday to Friday, 8am to 6pm. Both partners will need their National Insurance numbers.
• Post: Write to HMRC Pay As You Earn, BX9 1AS, including both partners' full names, National Insurance numbers, dates of birth, and confirmation of eligibility. This is the slowest method.

How and When You Receive the Refund

Backdated Years (2022/23 to 2025/26)

The refund for backdated years is paid to the higher-earning partner (the one who was overtaxed). HMRC will pay this:

• Directly into the bank account registered with HMRC (the fastest method — usually within a few weeks of the claim being processed)
• Or by cheque to the registered address

HMRC's processing time for Marriage Allowance backdating claims is typically 4 to 8 weeks from submission. During busy periods (such as the post-January SA rush), it can take longer.

Current Year (2026/27)

For the current tax year, HMRC adjusts the higher earner's tax code to give them the extra allowance. For a basic rate taxpayer, this will appear as a code of approximately 1384M (1257 + 127 extra = 1384, with M suffix denoting Marriage Allowance). This reduces their monthly tax deduction going forward.

The lower earner's code will show the N suffix (e.g., 1130N), reflecting their reduced Personal Allowance (£12,570 − £1,257 = £11,313).

Common Questions and Edge Cases

What If the Lower Earner Has Dividend Income or Rental Income?

If the lower earner has investment income or rental income — even if it is modest — this counts towards their total income for the Personal Allowance test. They can still claim Marriage Allowance provided their total income from all sources is below £12,570.

What If the Higher Earner's Income Fluctuates?

If the higher earner had income above £50,270 in some years but not others, they would not qualify for those years where they were a higher rate taxpayer. You can still claim for the years in which they were within the basic rate band.

What If We Are Getting Divorced?

Marriage Allowance transfers end in the year of legal separation (decree absolute for divorce, dissolution for civil partnerships). HMRC will revoke the allowance from the date of separation, and any underpayment by the higher earner for the remainder of the year will be collected via tax code or Self Assessment.

What If One Partner Is Scottish?

Scottish Income Tax has different bands. If the receiving partner pays Scottish Income Tax:

• They get the benefit at the Scottish intermediate rate (21%) rather than the UK basic rate (20%)
• The saving is therefore slightly higher in Scotland: £1,257 × 21% = £263.97

Is Marriage Allowance Worth Claiming?

For eligible couples, Marriage Allowance is one of the simplest and most valuable tax reliefs available. With no ongoing paperwork after the initial claim, and up to £1,008 available immediately from backdating, the only reason not to claim is if you are not eligible.

The online process takes around 10 minutes and HMRC's system then handles the adjustments automatically each year until the arrangement is cancelled or eligibility changes.

Summary

If you are married or in a civil partnership, one partner earns below £12,570, and the other earns between £12,571 and £50,270, you are almost certainly eligible for Marriage Allowance. By claiming now and backdating to 2022/23, you could receive up to £1,008 as a cash lump sum. The claim takes 10 minutes online via GOV.UK. Once set up, the ongoing saving of £252 per year is applied automatically through your tax code with no further action required.