The question is, should the deduction for marriage allowance (£212 in 2015/16) also reduce the payments on account for next year?
As the marriage allowance is taken off after the tax liability is arrived at, indeed the liability shown on the tax return does not have the deduction applied at all, I had thought it would not, that the POA would remain at 50% of the original liability per the return.
IRIS also appears to agree with me as it does not reduce the POA even while correctly applying the marriage allowance to the liability on the computation.
HMRC however have sent us a revised computation for one of our clients on which they have amended the POA to account for marriage allowance. This is the sixth or seventh return I have put in to which marriage allowance is to be applied but the first time they have sent such a letter. Having searched about I can't find anything definitive to say who is in the right here though obviously I'd rather not call HMRC to complain since it's in our client's interest to go with their figures.
Do I call HMRC to tell them it's wrong? Call IRIS to tell them their software is wrong? Wait and see? Does anyone really know how this mysterious allowance works?