In the UK, Student Loans are primarily provided by the state-owned Student Loans Company. Interest begins to accumulate on each loan payment as soon as the student receives it, but repayment is not required until the start of the next tax year after the student completes (or abandons) their education.
Payments only start if tax year earnings come over the ‘repayment threshold’ in force at the time.
Earnings are calculated before taking off tax or National Insurance contributions (NIC), or pension contributions. The repayment threshold is different depending on whether there is a Plan 1, Plan 2 or Plan 4 loan in place.