HMRC recently published a reminder targeted at married couples with an unused personal tax allowance. They said:
Marriage Allowance allows married couples or those in civil partnerships to share their personal tax allowances if one partner earns an income under their Personal Allowance threshold of £12,570, and the other is a basic rate taxpayer.
Eligible couples can transfer 10% of their tax-free allowance to their partner, which is £1,260 in the 2021-22 tax year. It means couples can reduce the tax they pay by up to £252 a year. Couples can apply any time, backdate their claims for any of the 4 previous tax years and receive a payment of up to £1,220 at a time when they need it most.
Married couples may have experienced a change in their circumstances which could now mean they are eligible for Marriage Allowance, including:
a recent marriage or civil partnership
one partner has retired and the other remains working
a change in employment due to COVID-19
a reduction in working hours which means their earnings fall below their Personal Allowance
unpaid leave or a career break, or
one partner is studying or in education and not earning above their Personal Allowance
If a spouse or civil partner has died since 5 April 2017, the surviving person can still claim by contacting the Income Tax helpline.
Marriage Allowance claims are automatically renewed every year.