Marriage Allowance calculator

Marriage Allowance transfers a fixed 10% slice of the Personal Allowance regardless of exactly how much of it the lower earner is using — even if they earn £0 or £12,000, the transferable amount is the same £1,260, worth the same £252 a year (20% of £1,260) to the recipient.

No — one of you specifically needs income below the £12,570 Personal Allowance to have spare allowance to transfer. If you're both earning above that (even if neither of you is higher-rate), there's nothing spare to give.

Yes — HMRC allows backdated claims for up to 4 previous tax years that you were eligible for but didn't claim, on top of the current year, using the slider above. The Personal Allowance has been frozen since 2022/23, so every year in that window is worth the same £252 — you don't need each year's figures to differ for this to be accurate.

Base it on the higher earner's (the recipient's) main residence — Scotland's higher-rate threshold (£43,662) is lower than the rest of the UK's (£50,270), because Scotland's income tax bands work differently, so it directly affects whether the recipient still qualifies.

The lower earner (the one with spare Personal Allowance) is the one who applies to HMRC to transfer it — but the tax saving lands on the higher earner's bill, via an adjusted tax code or Self Assessment. This calculator shows the outcome either way, regardless of who initiates the claim.

No — they're different. Marriage Allowance (this calculator) is for any married couple or civil partnership meeting the income rules. Married Couple's Allowance is a separate, more generous relief only available if at least one of you was born before 6 April 1935 — a much smaller group.