HMRC say they have procedures to avoid a taxpayer paying too much in relation to income contingent student loans.
However, when advisers complete a self assessment tax return, they may identify that the outstanding loan is less than the calculated amount to be paid on the return.
An application can be made for a specified amount to be informally stood over, but HMRC say if the sum is subsequently determined to be payable, it will attract interest (backdated to 31 January when the payment first became due) and possibly a surcharge.
Page five of the guide Collection of Student Loans for SA Customers provides more detail regarding overpayments and how to apply for an informal stand over.