missb

Good evening. About to submit my tax return but have discovered I am being charged for marriage allowance which is £251. we do have an account set up, however this was set up and we married in 2016. My tax return last year did not want £251 off me, even though the marriage allowance was in place. It did not lower my allowance then and I have roughly made around the same which is below the normal allowance. Why this year has it taken the allowance off but not last year? I dont understand. This has not made us any better off as I am the lower earner and dont earn enough to pay tax, yet I have to pay £251