How it works
What makes UK student loans different
Unlike most loans, a UK student loan behaves more like a graduate tax with a cap than a debt. There's no fixed monthly minimum, no impact on your credit file, no collections if you don't earn enough, and any balance unpaid at the plan's write-off point (25 to 40 years after study) is wiped — regardless of how much is left.
That fundamentally changes how to think about overpaying. For many graduates (especially Plan 2/Plan 5), paying early is financially worse than paying the minimum — because the balance will likely never be cleared before write-off anyway.
The five plans in 2025/26
| Plan | Who | Threshold | Rate | Write-off |
|---|---|---|---|---|
| Plan 1 | Pre-Sept 2012 UK undergrads (England/Wales); Scotland & NI ongoing | £26,065 | 9% | 25 years after April of repayment due or age 65 |
| Plan 2 | Sept 2012–July 2023 English/Welsh undergrads | £28,470 | 9% | 30 years after April of repayment due |
| Plan 4 | Scottish undergrads (post-2007) | £32,745 | 9% | 30 years after April of repayment due |
| Plan 5 | English undergrads starting Aug 2023 onwards | £25,000 | 9% | 40 years after April of repayment due |
| Postgraduate Loan | English/Welsh PG from 2016/18 onwards | £21,000 | 6% | 30 years after April of repayment due |
How the deduction works in practice
Your employer looks at each payslip period (week or month). If your pay in that period (before pension/salary sacrifice but after pre-tax benefits) annualises above your threshold, they deduct the % of the excess. It's done separately for each payslip, so a one-off bonus can push a month's deduction higher than average.
The amounts collected are sent to HMRC, which passes them to the Student Loans Company (SLC). Plan 1 and Plan 4 are reconciled annually; Plan 2, 5 and Postgraduate have a contribution table by paydate. Multiple plans run at the same time for people with both undergrad and postgrad loans — you pay 9% + 6% = 15% over their respective thresholds.
Example: Plan 2, £40,000 salary
Above threshold = 40,000 − 28,470 = £11,530.
11,530 × 9% = £1,037.70/year, or about £86.50/month.
Example: Plan 5, £30,000 salary
Above threshold = 30,000 − 25,000 = £5,000.
5,000 × 9% = £450/year, or £37.50/month.
Example: Plan 2 + Postgraduate, £45,000 salary
Plan 2: (45,000 − 28,470) × 9% = £1,487.70.
Postgraduate: (45,000 − 21,000) × 6% = £1,440.
Total: £2,927.70/year or ~£244/month on top of Income Tax and NI.
Interest: a moving target
Interest on student loans is not the same as a commercial loan. It's set by the government and tied mostly to the Retail Prices Index (RPI):
- Plan 1 — Lower of RPI and Bank of England base rate + 1%.
- Plan 2 — While studying: RPI + 3%. After graduation: sliding scale from RPI to RPI + 3% depending on income (capped at the Prevailing Market Rate for commercial loans).
- Plan 5 — RPI only, while studying and after.
- Plan 4 — Lower of RPI and Bank of England base rate + 1%.
- Postgraduate — RPI + 3% throughout.
Why the rate caps matter
The rates change in September each year. For Plan 2, interest rarely matters if you're unlikely to clear the loan before write-off; for Plan 5 with its 40-year term, more people will clear.
Should you overpay your student loan?
Largely depends on the plan and your earnings trajectory:
- Plan 2, average earner — almost certainly not. You'll keep paying 9% for 30 years regardless of balance; overpayments just vanish into a balance you were going to write off.
- Plan 2, high earner (£70k+) — maths changes. If you'd clear the loan before year 30 anyway, overpaying saves real interest.
- Plan 5, most earners — with 40 years to clear, a bigger share of borrowers will fully repay. Review every 5 years or so.
- Plan 1 / Plan 4 — low interest; rational to pay minimum.
- Postgraduate loan — higher interest and only 30-year term; if combined with a well-paying career, overpaying may save money.
Common mistakes
- Not telling a new employer you have a loan. HMRC will catch up eventually but you may get a surprise back-deduction.
- Overpaying because you hate the balance. Look at the projected repayment vs write-off first.
- Paying off the last year too aggressively. You can request a switch to Direct Debit for the final 23 months to avoid accidentally overpaying.
- Forgetting that bonuses annualise. A one-off £10k bonus can push a monthly deduction above your expected figure.
Living abroad while repaying a UK student loan
Leaving the UK doesn't cancel the loan. Anyone planning to be overseas for more than three months must notify the Student Loans Company using their overseas income assessment form. You'll then be placed on a fixed repayment schedule based on overseas thresholds — which are different from the UK ones and adjusted for the cost of living in your destination country.
Brazilian graduates returning home or moving to Portugal, for example, face a UK SLC repayment schedule calculated on their local salary converted to pounds, with the threshold adjusted down (Brazil) or up (Switzerland, UAE). Ignore the notification, and SLC applies a fixed monthly charge — usually the highest expected payment based on your last-known salary — until you respond. Fixed charges can be hundreds of pounds a month, even when your real income is zero.
Keep your UK bank account open if you can; most SLC overseas payments are taken by Direct Debit, and some countries' banks charge heavy fees for cross-border payments to the UK.
Timing tricks to minimise what you pay
A few legitimate strategies reduce what you repay over the life of the loan.
Salary sacrifice pensions
Student loan repayments are calculated on pay after salary sacrifice but before tax and NI. Sacrificing £5,000 into pension reduces your student loan bill by 9 % × £5,000 = £450/year on Plan 2/5. Over a 30- or 40-year horizon, that can easily exceed £10,000 in avoided repayments.
Timing bonuses
Because each payslip is assessed individually, a bonus in a single pay period can trigger a larger deduction than the same amount spread evenly. If you have flexibility, ask to split a bonus over multiple months.
The "final 23 months" Direct Debit switch
When your balance gets close to zero, PAYE's lag means you often overpay by hundreds of pounds before SLC refunds you. You can ask SLC to switch you to Direct Debit in the last 23 months of repayment — you pay the exact amount needed and avoid paperwork later.
Year-end refunds
If you earned above threshold in some months but your annual salary was below threshold (perhaps due to a redundancy or sabbatical), Plan 1 and Plan 4 refund automatically. For Plan 2, 5 and Postgraduate you have to apply after year-end to recover it.
Maintenance loans, grants and the bigger picture
Tuition fees are only half the story. Most students also borrow a maintenance loan — up to £13,762/year in London for 2025/26 — to cover rent, food and bills. It's means-tested: students from households earning above £62,341 get the minimum. The full maintenance figure is added to the tuition-fee loan to form your total balance, though both are repaid together under the same plan.
Scotland, Wales and Northern Ireland have separate grants and bursaries that do not have to be repaid. Welsh students in particular benefit from a generous maintenance grant that reduces the debt taken on for living costs.
Student loan and mortgage affordability
Lenders don't see the student loan on your credit file, but they do look at the monthly deduction on your payslip. A £250/month deduction effectively reduces the maximum mortgage you can borrow by roughly £30,000–£50,000, depending on the lender's income multiple.
This surprises many first-time buyers who assumed the loan wouldn't count. Two strategies help: overpaying the loan just before applying for a mortgage (reducing the balance but not the deduction), or restructuring income to include bonuses, which most lenders only partly count. Neither removes the impact, but both can soften it at the margin.
Career trajectories and the "effective tax" lens
Because the student loan is a 9 % deduction with a 30- or 40-year horizon, a useful mental model is to treat it as an additional marginal income tax during your working life. The effective marginal rates look like this for someone on Plan 2 or 5:
| Band | Income Tax | NI | Student Loan | Total marginal |
|---|---|---|---|---|
| £12,571 – £25,000 | 20 % | 8 % | 0 % | 28 % |
| £25,001 – £28,470 (Plan 5 only) | 20 % | 8 % | 9 % | 37 % |
| £28,471 – £50,270 | 20 % | 8 % | 9 % | 37 % |
| £50,271 – £100,000 | 40 % | 2 % | 9 % | 51 % |
| £100,001 – £125,140 | 60 % effective | 2 % | 9 % | 71 % |
| Over £125,140 | 45 % | 2 % | 9 % | 56 % |
Five life events that reshape your repayments
Life rarely runs in a straight line. Five events change your student loan situation materially.
Taking a year off work
Deductions stop as soon as your monthly earnings fall below the threshold. Interest still accrues, but you pay nothing until you're back above it. Don't panic-overpay from savings; you may never reach that balance before write-off.
Starting self-employment
Student loan is then collected via Self Assessment every January, not month by month. Budget for a single lump-sum repayment and keep at least 10 % of your profits in a separate account for this bill.
Being made redundant
A redundancy payment up to £30,000 is tax-free and also excluded from student loan calculations. Anything above that is treated as ordinary earnings and can trigger a large one-off repayment.
Becoming a parent and using Shared Parental Leave
Shared Parental Pay is treated as earnings for student loan purposes. For many couples, though, pay drops below threshold during leave and deductions pause naturally.
Hitting your highest-earning decade
For Plan 2 and Plan 5 graduates reaching £70k–£90k salaries in their 30s or 40s, the loan can start shrinking quickly. That's the moment to revisit the "should I overpay" question with fresh numbers.