UK Marriage Allowance Tax Relief Calculator & Guide 2026

What Marriage Allowance Actually Does

Marriage Allowance lets an eligible spouse or civil partner transfer 10% of their Personal Allowance to the other partner. For 2026-27, the standard Personal Allowance is £12,570, so the transferable amount is £1,260. That £1,260 is an allowance transfer, not a guaranteed £1,260 tax refund. The couple's actual saving depends on how much tax each partner would otherwise pay.

Exact Calculation: £1,260 Transfer Does Not Guarantee £252 Saving

The maximum saving is calculated as £1,260 × 20% = £252, but this is only the maximum standard saving. GOV.UK provides an example where the lower earner has £11,500 income and transfers £1,260: their taxable income becomes £190, while the recipient's taxable income falls by £1,260. The couple therefore saves £214, not £252, because the transferor starts paying £38 of tax.

Who Is Eligible for Marriage Allowance?

The couple must be married or in a civil partnership. Normally, the lower-income partner must have income below the Personal Allowance and the receiving partner must pay Income Tax at the permitted rate. GOV.UK describes the usual lower-income condition as income below the £12,570 Personal Allowance and the usual England/Wales/Northern Ireland recipient range as £12,571 to £50,270 before Marriage Allowance. The detailed test can be affected by savings, dividends and other income.

Scottish Marriage Allowance Recipient Test

Scotland has separate Income Tax bands. For 2026-27, a recipient can qualify for Marriage Allowance if they pay Scottish starter, basic or intermediate rate, which generally covers taxable income from £12,571 to £43,662 with the standard Personal Allowance. The higher-rate threshold begins at £43,663.

PAYE Tax Codes M and N

When HMRC applies Marriage Allowance through PAYE, the recipient's tax code normally ends in M, while the transferor's normally ends in N. For a simple standard-Personal-Allowance example, 1257L can become approximately 1383M for the recipient and 1131N for the transferor. Actual tax codes can differ if HMRC needs to make other coding adjustments.

Automatic Renewal and When You Must Cancel

A successful Marriage Allowance claim normally continues automatically each year until it is cancelled. HMRC requires cancellation if the relationship ends, if income changes so that the couple is no longer eligible, or if the claimant no longer wants the allowance. Either partner can cancel when the relationship itself has ended; otherwise the person who made the claim normally cancels.

Self-Employed, Pension and Other Income

Marriage Allowance is not restricted to PAYE salary earners. Self-employed people and pensioners can qualify where the income/rate conditions are satisfied. HMRC also states that living abroad does not automatically prevent a claim if the relevant Personal Allowance is available.

Marriage Allowance and Married Couple's Allowance Are Different

Marriage Allowance should not be confused with Married Couple's Allowance. Married Couple's Allowance is a separate relief available where one spouse or civil partner was born before 6 April 1935, subject to its own conditions. A couple cannot receive both allowances at the same time.

2025-26 FIG Interaction: Marriage Allowance Can Be Lost

A specialist 2026 point is the interaction with the UK's Foreign Income and Gains (FIG) regime. HMRC's 2026 Self Assessment notes state that if an individual makes a foreign income claim, foreign gains claim or Overseas Workday Relief election for 2025-26 under FIG, they lose entitlement to Marriage Allowance for that tax year. This is a specific interaction that should be checked rather than assuming every otherwise-eligible couple receives Marriage Allowance.

Marriage Allowance in Self Assessment

If the couple uses Self Assessment, the transferor completes the Marriage Allowance section of their return, while the recipient leaves that section blank. If both file Self Assessment, HMRC says the transferor should file their return at least 3 days before the recipient's return.

Refund and PAYE Adjustment Mechanics

HMRC can apply Marriage Allowance by changing the recipient's PAYE tax code or by incorporating it into a Self Assessment calculation. For historical overpayments, the refund mechanism depends on HMRC's resulting tax calculation and the taxpayer's circumstances; it is not correct to promise a P800 cheque for every claim.

Practical 2026 Marriage Allowance Calculator Logic

A correct Marriage Allowance calculator should calculate the transfer amount first, then recompute the tax liability of both partners before and after the transfer. The result should be the actual reduction in combined Income Tax, capped by the statutory £252 maximum for a full £1,260 transfer at 20%. It should not simply output £252 for every eligible couple.

Common Calculator Errors to Avoid

A calculator that only multiplies £1,260 by 20% will overstate the saving for some couples. It also needs to distinguish Scotland from the rest of the UK, recognise that the transferor can become taxable, and avoid using salary alone as a complete proxy for taxable income.

Practical 2026 Marriage Allowance Workflow

A reliable calculator and guide should establish the couple's relationship status, identify the lower earner, check the relevant tax jurisdiction and income conditions, apply the £1,260 transfer and then calculate the combined tax before and after. It should separately handle PAYE, Self Assessment, pension and self-employed cases and check whether any special relief interaction removes eligibility.

Frequently Asked Questions (6)