CSLM13012 - FAQs: forms questions and answers: what do I do with a Start Notice issued in error?
The Student Loans Company (SLC) notifies HMRC when a borrower is due to start repaying their loan and HRMC automatically issues a start notice (SL1/PGL1) to the employer.
If the start notice refers to a borrower who you no longer, or have never employed, you can disregard the notice.
If the start notice refers to an employee then you must start deductions from the next available pay date. You cannot stop deductions becuase an employee tells you to.
Your employee should ask for a refund if they think they have overpaid their loan or contact SLC on 0300 100 0611 if they are not a student loan borrower.