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Postgraduate student loan repayment calculator (2026/27)

Master's / PhD loans from August 2016 onwards. £21,000 frozen threshold (lowest of any plan), 6% rate. Always stacks separately from any undergrad plan, combined max rate 15%.

Reviewed 29 April 2026 · 2026/27 rates verified
Plans you hold

Multiple undergrad plans → HMRC takes ONE 9% deduction at the lowest threshold (Student Loans Company allocates internally). Postgrad is separate at 6%.

Tax year

Plans 1, 2, 4 thresholds rose for 2026-27 (annual indexation); Plan 5 + Postgrad frozen.

Annual student loan repayment

£540

£45/month equivalent · 6% postgrad only

Show full breakdown

Where the maths goes

Annual income£30,000.00
Postgrad threshold£21,000.00
Income above postgrad threshold£9,000.00
Postgrad repayment @ 6.0%Separate 6% — added to undergrad if both held£540.00
Total annual repayment£540.00
Monthly equivalentHow it actually shows up on your payslip — divided by 12£45.00

Sensitivity: repayment at different incomes

Same plan set (postgrad). Useful for planning raises, day-rate increases, or contract renewals — your SL repayment grows linearly above the threshold.

IncomeAnnual SLMonthly
£25,000£240£20
£30,000£540£45
£40,000£1,140£95
£50,000£1,740£145
£60,000£2,340£195
£80,000£3,540£295
£100,000£4,740£395

How Postgrad actually works

Postgrad is the loan scheme for Master's and PhD students from August 2016 onwards. The mechanics: 6% of every pound of income above £21,000 (the lowest threshold of any plan). Repayments via PAYE for employees; via self-assessment for self-employed and Ltd directors.

The stacking model, why 6% not 9%

Postgrad ALWAYS stacks separately on top of any undergrad plan. The 6% rate exists because most Postgrad holders also hold an undergrad plan: combining 9% + 6% gives a 15% combined max rate, which the Treasury views as the politically-acceptable ceiling. If Postgrad were 9%, the combined rate would be 18%, pushing the marginal tax rate for higher-earning graduates with both loans above 65% (income tax + NI + 18%), which government has been unwilling to do.

Plan + Postgrad worked example

At £40,000 income with Plan 2 + Postgrad:

  • Plan 2: 9% × (£40,000 − £29,385) = £955/year
  • Postgrad: 6% × (£40,000 − £21,000) = £1,140/year
  • Total: £2,095/year, about £175/month of student loan deduction

Try other plan combinations in the calculator above by adding the relevant plans to the multi-select.

Interest at RPI + 3%

Postgrad charges RPI + 3%, the highest interest rate of any UK student loan plan, with no income-banded reduction. The high real interest combined with smaller typical balance (the loan caps around £12,000–£15,000) means voluntary overpayments are more attractive on Postgrad than on any other plan. Use MoneySavingExpert's calculator to model your specific case.

What this calculator doesn't cover

Frequently asked questions

What is the Postgraduate loan?
A separate loan scheme for English/Welsh students taking Master's or PhD courses from August 2016 onwards. Maximum loan around £12,167 (Master's) or larger for PhD. The repayment terms are different from undergrad: 6% rate (vs 9% for undergrad), £21,000 threshold (lowest of any plan), and 30-year write-off. Crucially it ALWAYS stacks on top of any undergrad plan you hold, it never replaces undergrad repayments.
Why is the rate 6% instead of 9%?
Policy choice when Postgrad was introduced in August 2016. The 6% rate plus £21,000 lowest-threshold combines to give a moderate level of repayment for typical Master's earners while not piling 9% on top of an existing 9% undergrad rate. Without the lower 6%, someone with both undergrad + Postgrad would be paying 18% above the threshold, politically unacceptable. The current 9% + 6% = 15% combined max rate is HMRC's policy compromise.
What's the Postgrad threshold for 2026/27?
£21,000, frozen since the loan was introduced in 2016 and remains frozen. Postgrad and Plan 5 are the two frozen-threshold plans; Plans 1, 2, and 4 are uplifted annually by RPI. The freeze is a deliberate fiscal-drag policy: as wages rise nominally, more workers cross the threshold and start repaying.
Postgrad ALWAYS stacks separately: explain?
If you hold an undergrad plan + Postgrad, you pay BOTH deductions independently. They're not combined like multiple undergrad plans (which take ONE 9% deduction at the lowest threshold). So a Plan 2 + Postgrad holder at £40,000 income pays: Plan 2 × (40,000 − 29,385) × 9% = £955 + Postgrad × (40,000 − 21,000) × 6% = £1,140 = £2,095 total. The Postgrad deduction is calculated and deducted separately from your undergrad deduction.
What's the maximum combined rate?
15%. That's 9% undergrad + 6% Postgrad. This applies to income above the higher of the two thresholds you hold. For example: Plan 2 + Postgrad = 15% on income above £29,385 (the Plan 2 threshold; Postgrad threshold £21,000 is lower so already passed). Plan 1 + Postgrad = 15% on income above £26,900. Plan 4 + Postgrad = 15% on income above £33,795 (Plan 4 has the highest undergrad threshold).
What's Postgrad's interest rate?
RPI + 3%, the highest interest rate of any UK student loan plan. There's no income-banded reduction like Plan 2 has. The 3% real interest rate combined with the 30-year write-off and the typically smaller balance means many Postgrad borrowers DO repay in full before write-off, unlike Plan 5 borrowers who often won't.
When does Postgrad get written off?
30 years after the April you became eligible to repay (same as Plans 2 and 4). For someone who completed a Master's at 23 and started repaying at 24, write-off is at age 54. Smaller balance + relatively higher interest means most Postgrad borrowers do clear the loan before write-off, but for those who never reach high earnings consistently the 30-year clock can still run out.
Should I make voluntary overpayments?
More likely yes than for other plans, especially if you're a higher earner. Postgrad's 3% real interest is the highest of any plan, and the smaller balance means voluntary overpayments can clear the loan years before write-off, eliminating the high interest charge. The MoneySavingExpert calculator (mse.me/student-finance) is the standard tool, it usually flags Postgrad as the only plan where overpayment makes sense for moderate earners. One exception: if you also have an undergrad plan with significant balance, prioritise Postgrad clearance first because of the rate differential.

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Reviewed: 29 April 2026 · See how we calculate · not financial advice.