Married Couples Allowance (MCA) is an age related allowance applicable if at least one spouse is born before 6th April 1935. It could reduce your tax bill by between £353 and £912.50 a year.
You can claim Married Couple’s Allowance if all of the following criteria apply:
Transferring your Married Couples Allowance to your spouse or civil partner
Start of the year
It is possible to transfer the whole of the minimum amount to your spouse or civil partner prior to the beginning of the tax year. A form 18 will need to be completed for this purpose.
End of the tax year
If you do not pay tax or the tax bill is not high enough to use up all of the MCA, it is possible to use form 575 (Notice of transfer of surplus Income Tax allowances) after the end of the tax year to transfer any unused allowance to your spouse or civil partner.
Where to enter claim for Married Couple's Allowance in TaxCalc?
HMRC Forms Mode
*Please note that if you are claiming surplus allowance, you need to go to Tax Calculation > Page 2 > Box 13 to enter the surplus amount
For additional information please refer to the HMRC page on Married Couples Allowance