Question to the HM Treasury:

To ask His Majesty's Government what research, if any, they have carried out or commissioned on the reasons for the level of take up of the marriage allowance.

Marriage Allowance allows a spouse or civil partner to transfer ten per cent of their income tax personal allowance, as long as the partner is not paying tax at higher rates.

The most recent estimates for the cost and uptake of Marriage Allowance can be found in HMRC’s published tax relief statistics, last updated in January 2026. This is available at the following link: https://www.gov.uk/government/statistics/tax-reliefs/tax-relief-statistics-january-2026.

The number of Marriage Allowance claimants was estimated at 2,440,000 for the 2023-2024 tax year and the estimated cost is projected to be £590 million for the 2025-2026 tax year. Estimates of the number of claimants are the latest available and reflect only successful claimants up to that point in time and not the anticipated full take up when all backdated claims have been made in future tax years (up to 4 years later).

Data for previous tax years (up to 6 years) on the cost and uptake of Marriage Allowance can be found in the non-structural tax relief statistics, which is available at the following link https://www.gov.uk/government/statistics/main-tax-expenditures-and-structural-reliefs/non-structural-tax-relief-statistics-december-2024. This is summarised below.

HMRC does not produce household-level analysis for Marriage Allowance eligibility.

HMRC’s ongoing communications campaign for Marriage Allowance seeks to raise awareness of the eligibility criteria for the allowance, encourage take-up and educate customers on how to claim. It consists of regular promotional activity throughout the year bolstered by paid-for activity at key times of increased interest or engagement in the allowance for customers.