Because Plan 5 has a lower threshold (£25,000) and a much longer life (40 years), the math on overpayments has completely flipped.
Unlike older “Plan 2” graduates, 65% of Plan 5 graduates are now expected to pay their loan back in full. This means that for many, every £1 you overpay today could actually save you £2 or £3 in future “interest and tax” deductions.
Here is the 2026/27 Decision Matrix to help you decide if you should throw extra cash at the Student Loans Company (SLC).
The Plan 5 “Should I Overpay?” Matrix
| If your situation is… | Overpay? | The Strategic Reason |
| High Earner (£50k+) | YES (Consider it) | You will almost certainly clear the debt before the 40-year wipe-off. Overpaying early kills the RPI interest before it compounds. |
| Middle Earner (£30k–£45k) | ONLY IF… | You have already maxed your ISA and have a mortgage deposit ready. You are on the “edge” of paying it back; overpaying might help, but cash-in-hand is safer for now. |
| Low Earner (<£30k) | NO | You might never pay the loan back in full. If the loan is going to be written off in 2066 anyway, any overpayment you make today is effectively a donation to the Treasury. |
| Saving for a House | NO | A mortgage lender cares more about your deposit size than your student loan balance. Keep the cash in a Lifetime ISA (LISA) instead. |
| Debt-Averse (Psychological) | MAYBE | If the “red number” on your SLC statement causes you stress, the mental relief of clearing it has value—but the “math” says only do this if you have no other high-interest debt. |
The “ISA vs. Loan” Calculation (2026)
Because Plan 5 interest is set at RPI only (currently 3.2%), the decision is a simple “Rate vs. Rate” battle:
- The Loan Cost: Your debt grows by 3.2%.
- The ISA Gain: A standard Cash ISA in 2026 pays around 4.0%–4.5%.
- The Winner: In this scenario, your money is “working harder” in the bank than it is by paying off the loan. You are effectively making a 1% profit by keeping the cash in savings.
The “Golden Rule” for 2026 Graduates
Never overpay your student loan if you still have:
- Credit Card Debt (usually 20%+)
- Unfilled ISA Allowance (tax-free growth)
- No Emergency Fund (you can’t “withdraw” a student loan overpayment if your car breaks down!)
Other Plan 5 articles
You can also try our Student Loan Early Repayment Planner calculator or our First Plan 5 Deduction in April 2026 article
