Self assessment and underpayment restriction query.

tamlem

I am completing self assessment online for the first time. I completed it with little trouble but have a query re. the coding notice/underpayment restrictions.

There is a question that asks if your 2012-13 coding includes any underpayment restriction and then another question that asks if your 2013-14 coding includes an underpayment restriction for 2012-13.

My 13-14 coding does include an underpayment restriction- when I moved jobs 3 years ago my new payroll messed up my coding and then hmrc told me i'd underpaid and that they would be taking it back via my personal allowance. I'm not sure exactly what year this was, prob (11-12) but it wasn't for 2012-13, my tax code was correct then.

If I enter the underpayment restriction onto the Self assessment system for my 2013-14
coding my calculation tells me that HMRC owe me about £3600!! but in actual fact I think I owe them £400- child benefit charge.

So my question is, does this underpayment restriction for my 2013-14 coding not have to be entered anywhere in my self assessment form, because it doesn't relate to the 2012-13 tax year? I'm guessing it will be next year that it will become relevant as I will enter it for my 2013-14 coding/ return? The question asks specifically do you have an underpayment restriction from 2012-13 on your 2013-14 coding so I assume I don't enter it but wanted to check?

Many thanks