How UK student loan repayments actually work
UK student loans are not like commercial debt. You repay a percentage of what you earn above a threshold, not a fixed monthly amount. If your salary drops, your repayments drop. If you stop earning, you stop repaying. After a set number of years, whatever's left is written off.
This is why the most important question for most graduates isn't "how do I pay this back faster?" — it's "will I even pay it back at all?" The answer for the majority of Plan 2 borrowers is no. The Institute for Fiscal Studies estimates only around a quarter of Plan 2 borrowers fully repay before write-off. For everyone else, voluntary overpayments are money given away.
What's fixed and what changes
Two things confuse new graduates: the difference between the repayment rate and the interest rate. They're separate, and they behave very differently.
The repayment rate is fixed
9% for Plan 1, 2, 4, and 5. 6% for Postgraduate loans. These percentages are written into UK legislation and have not changed since the system began in 1998. They apply to your earnings above your plan's threshold — so if you earn £30,000 on Plan 2 (threshold £29,385), you're paying 9% of £615, not 9% of £30,000.
The interest rate fluctuates — quarterly
This is the part most people don't realise. Student loan interest rates are reset four times a year (March, June, September, December) based on RPI inflation and the Bank of England base rate. During 2022-23, when RPI hit double digits, Plan 2 interest briefly reached 8%. It's currently 6.2% but could rise or fall at the next review.
Crucially: the interest rate does not affect your monthly repayment. Your monthly amount is always 9% (or 6%) of income above the threshold. Interest only changes how fast your balance grows — and therefore how much gets written off versus repaid.
The threshold also changes
Repayment thresholds are reviewed every April. For 2026-27, Plan 2 rose from £28,470 to £29,385. Plan 5's threshold is frozen at £25,000 until at least April 2027. Threshold changes alter your monthly repayment directly, so it's worth checking each April.
2026-27 repayment thresholds at a glance
| Plan | Threshold | Rate | Write-off |
|---|---|---|---|
| Plan 1 | £26,900 | 9% | 25 years |
| Plan 2 | £29,385 | 9% | 30 years |
| Plan 4 (Scotland) | £33,795 | 9% | 30 years |
| Plan 5 | £25,000 | 9% | 40 years |
| Postgraduate | £21,000 | 6% | 30 years |
Thresholds for the 2026-27 tax year (6 April 2026 to 5 April 2027). Source: gov.uk.
The biggest decision: should you overpay?
Most graduates assume overpaying is sensible. For UK student loans, that assumption is often wrong. If you'd never have repaid the full amount anyway, every extra pound you pay is a pound you'd otherwise have kept.
Try this: enter your salary and balance into the calculator above, then add a £100 monthly overpayment. If it tells you "overpaying does NOT save you money," that's because your loan would have been written off before you cleared it. The standard repayments alone would have done the job — and the government would have absorbed the rest.
The cases where overpaying does help: if you earn well above your threshold, started university more recently, have a smaller balance, or are on Plan 1 or Plan 4 (lower interest rates). The calculator shows you which camp you're in.
Read the full guide on whether to overpay →
Calculate by salary
Quick lookups for what each plan costs at common salary levels:
Common questions
When do 2026-27 thresholds take effect?
From 6 April 2026 to 5 April 2027. The new Plan 2 threshold of £29,385 represents a £915 increase from the 2025-26 figure. Plan 5 borrowers start repaying for the first time in April 2026.
Do student loans affect my credit score?
No. UK student loans do not appear on your credit file and do not directly affect your credit score. However, mortgage lenders consider monthly student loan deductions when assessing affordability — they reduce your disposable income.
What happens if I move abroad?
You still need to repay. SLC sets overseas thresholds adjusted for living costs in your new country. If you don't tell SLC about your income, they apply a fixed (often higher) amount. Tell them when you move.
Can I see my exact balance?
Yes — log in at gov.uk/sign-in-to-manage-your-student-loan. This calculator gives accurate estimates based on official figures, but only SLC has your exact day-by-day balance.
What if I have multiple plans?
If you have both Plan 1 and Plan 2 (rare — it happens if you returned to study), you repay against the lower threshold. If you have a Postgraduate Loan plus an undergraduate plan, both stack — you'll repay 6% above £21,000 for postgrad AND 9% above your undergrad threshold.