Hi,
You can review your claim for marriage allowance once you know your total income for the year.
If your savings interest pushes your income above £12570 this may then mean you will pay some tax.
If this happens you can then decide what is financially more beneficial for you as a couple.
If you cancel because of a change in income, the allowance will run until the end of the tax year (5 April)
Marriage Allowance
Thank you.