The Married Couple's Allowance (MCA) is available to elderly married couples or those in a civil partnership, where at least one member of the couple were born before 6 April 1935 (i.e. at least 83 years old). The allowance provides for tax relief by deducting 10% of the allowance from the amount of tax due on taxable income. The MCA can reduce a tax bill to zero but cannot result in a refund of tax.
For the new tax year, the maximum amount of married couple's allowance is £8,695. This means that qualifying claimants can receive a maximum deduction of £869.50 from their Income Tax bill. There is a minimum allowance of £3,360 which could get qualifying taxpayers a minimum deduction of £336.
The MCA should not be confused with the Marriage Allowance (MA), which came into force on 6 April 2015 and allows lower earning couples (of any age) to share part of their personal tax-free allowance. The MA allows the lower earning partner to transfer up to £1,190 (2018-19) of their personal tax-free allowance to a spouse or civil partner.