SL repayments: underpayments and overpayments: borrower fails to settle loan liability - SA case
If the borrower falls within Self Assessment then he or she will be responsible for self assessing in respect of Student Loan repayments, along with tax and NICs. If the borrower is also within PAYE, credit will be given for deductions made by the employer.
Any liability within SA will be included in the balancing payment, due on 31 January following the end of the tax year to which the repayments relate. Payments on account will not include any liability to Student Loans repayments.
If a borrower fails to pay outstanding Student Loans repayments or is late in making payment he may be liable to pay surcharges, interest on overdue payments and penalties inline with those that apply to the payment of tax.
You should therefore follow normal SA rules and procedures applying to unpaid tax and NICswhen considering unpaid Student Loan Repayments.