GOV.UK
Marriage Allowance
2. How to apply
You can apply for Marriage Allowance online.
If your application is successful, changes to your Personal Allowances will be backdated to the start of the tax year (6 April).
How your Personal Allowances change
HM Revenue and Customs (HMRC) will give your partner their extra allowance either:
- by changing their tax code - this can take up to 2 months
- when they send their Self Assessment tax return, if they’re self-employed
Your tax code will also change if you’re employed or get a pension. Your new code will reflect your new Personal Allowance and will end with ‘N’.
When Marriage Allowance stops
Your Personal Allowance will transfer automatically to your partner every year until one of you cancels Marriage Allowance or your circumstances change, for example because of divorce or death.