A couple who are married or in a civil partnership may be able to transfer some unused Personal Allowance from one partner to another.
This process must be initiated by the partner transferring the allowance OUT (usually the lower or non taxpayer) to their partner.
The partner receiving the extra allowance has had a transfer IN from their partner.
The process must be done directly with HMRC either via their website https://www.gov.uk/marriage-allowance or by telephone.
The person transferring their allowance OUT will need to supply their partner’s full name, National Insurance number, date of birth and date of marriage or civil partnership.
Once HMRC has accepted the transfer, they will automatically apply the change in tax to both partners’ tax accounts.
In order for the Ftax SA100 to accurately calculate your tax due, you should record transfers (both OUT and IN) on page TR5 of the Self Assessment tax return.
If you have transferred a Personal Allowance to your spouse or civil partner, then tick Transfer OUT and complete boxes 1 to 5.
If a Personal Allowance is being transferred to you, then simply tick Transfer IN. Do NOT complete boxes 1 to 5.
Please note that a Transfer IN will only affect your tax calculation if you are not a Higher Rate tax payer and both your Married Couples Allowance and Married Couples Surplus Allowance are zero.