CSLM11066 | FAQs: borrowers questions and answers: amount of repayments: made repayments but earn less than threshold

Suggested answer

As deductions are calculated on a non cumulative basis, your employer may still have deducted repayments in certain periods, even if your earnings for the year are less than the annual threshold. For example, if you were paid a bonus or overtime that put you over the threshold for your plan and or loan type in that period.

For more information on how to ask for refund if your annual income was below the threshold for a previous tax year, access gov.uk website.