Mortgage With a Student Loan: How Each Plan Changes What You Can Borrow

By Jake Stott, Knox Mortgages. Reviewed by an adviser authorised under Fort Advice Bureau, FCA FRN 972730. Published 27 September 2026. Last reviewed 27 September 2026.

A mortgage with a student loan is a normal mortgage taken out by someone still repaying a UK student loan. The loan does not appear on your credit file and does not stop you getting a mortgage. What it does is cut your take-home pay, and most lenders count that monthly deduction as an outgoing, which reduces how much they will lend.

That is the whole story in two sentences, and most of the internet gets half of it wrong. Graduates are told either that a student loan “doesn’t count” or that a £60,000 balance will wreck their application. Neither is true. The balance barely matters. The monthly deduction on your payslip is what lenders see, and the size of that deduction depends on your plan and your salary, not what you owe. This guide covers the 2026/27 thresholds for every plan, how lenders treat the deduction, a worked example with the arithmetic shown, whether to overpay the loan or save a bigger deposit, and the specific reasons student loan cases get declined.

Does a student loan affect getting a mortgage?

Yes, but only through affordability, not through your credit score. Income-contingent student loans from the Student Loans Company are not reported to the credit reference agencies, so they do not show on your Experian, Equifax or TransUnion file and do not lower your score. A lender running a credit search will not see one.

They will see it on your payslip. Student loan repayments are taken through PAYE, so they appear as a deduction alongside tax and National Insurance, usually labelled “SL” or “Student Loan” and “PGL” for a Postgraduate Loan. Underwriters read payslips line by line. Every mainstream affordability model then asks what you have left each month after committed spending, and the student loan repayment is committed spending: you cannot stop paying it while your income stays above the threshold.

So the answer to “does student loan affect mortgage” is yes for how much you can borrow, and no for whether you are acceptable as a borrower. A graduate with a student loan and a clean credit file is a perfectly ordinary mortgage applicant.

How much do you repay on each student loan plan in 2026/27?

You repay a fixed percentage of your income above a threshold, and the threshold depends on your plan. For the 2026/27 tax year (from 6 April 2026) the figures published on gov.uk are:

Plan	Who has it	Annual threshold 2026/27	Monthly threshold	Rate above threshold
Plan 1	England or Wales students who started before September 2012; Northern Ireland students	£26,900	£2,241	9%
Plan 2	England or Wales students who started between September 2012 and July 2023	£29,385	£2,448	9%
Plan 4	Scottish students	£33,795	£2,816	9%
Plan 5	England students who started from August 2023	£25,000	£2,083	9%
Postgraduate Loan	Master’s or doctoral loan (England or Wales)	£21,000	£1,750	6%

Source: gov.uk, “Repaying your student loan: what you pay”, checked September 2026. The government confirmed in the November 2025 Budget that the Plan 2 threshold will be frozen at £29,385 from April 2027 until April 2030, so a Plan 2 graduate who gets pay rises over the next few years will see their deduction grow faster than it has in the past.

If you hold a Postgraduate Loan alongside Plan 1, 2 or 4, you pay both at once: 6% above £21,000 for the Postgraduate Loan plus 9% above your undergraduate threshold. That combination is where the mortgage impact really starts to bite.

What does the deduction look like at different salaries?

The monthly figure is what a lender plugs into its affordability calculation, so it is worth knowing yours before you apply. Here is the monthly repayment at three salaries, calculated as (salary minus threshold) multiplied by the rate, divided by 12:

Plan	£30,000 salary	£38,000 salary	£50,000 salary
Plan 1	£23.25	£83.25	£173.25
Plan 2	£4.61	£64.61	£154.61
Plan 4	£0	£31.54	£121.54
Plan 5	£37.50	£97.50	£187.50
Postgraduate Loan	£45.00	£85.00	£145.00
Plan 2 plus Postgraduate Loan	£49.61	£149.61	£299.61

Two things jump out. First, Plan 5 graduates pay more than Plan 2 graduates at every salary, because the threshold is £4,385 lower. Second, the balance appears nowhere in this table. A Plan 2 graduate owing £25,000 and one owing £75,000 on the same salary have exactly the same deduction, and so exactly the same mortgage impact. Your payslip figure may differ slightly from these numbers because repayments are calculated per pay period, so overtime or a bonus month pushes that month’s deduction up.

How do lenders treat student loan repayments?

Lenders fall into two broad camps, and which camp you land in changes your maximum loan.

Lenders that deduct the repayment as a commitment. This is the majority approach on the high street. The lender takes your gross income, works out your net pay, then subtracts your committed outgoings, including the student loan, before stress-testing the mortgage payment at a higher rate. Nationwide’s intermediary criteria, for example, list student loans under “non-credit commitments (monthly outgoings)” that must be entered on the application (checked September 2026). Under this approach every pound of monthly student loan repayment removes a chunk of borrowing, because the lender is effectively asking how much mortgage that pound could have serviced at a stressed rate.

Lenders that apply a lighter touch. Some lenders use a model that leans more on a gross income multiple and reduces the income figure by the annual repayment, rather than capitalising the monthly payment at a stress rate. The effect is a much smaller reduction. Criteria change frequently and lenders do not always publish the fine detail of their affordability engines, so we test the real figure on each lender’s calculator for the specific case rather than relying on a rule of thumb.

No mainstream lender will ignore a student loan you have declared if it is visible on your payslip. What varies is how heavily it is weighted. That weighting is where a broker earns their keep.

Worked example: how much less can a Plan 2 graduate on £38,000 borrow?

Take a single first-time buyer on a £38,000 basic salary, Plan 2 student loan, no other debts, clean credit, buying with a 10% deposit. Their student loan deduction is:

(£38,000 minus £29,385) × 9% = £8,615 × 9% = £775.35 a year, or £64.61 a month.

Lender approach	Calculation	Maximum borrowing	Reduction
Student loan not factored (income multiple only, for comparison)	£38,000 × 4.5	£171,000	£0
Light touch: annual repayment taken off income before the multiple	(£38,000 minus £775.35) × 4.5 = £37,224.65 × 4.5	£167,511	£3,489
Full commitment: monthly repayment capitalised at a 7% stress rate over 30 years	£64.61 × 150.31 (annuity factor) = £9,712 removed	£161,288	£9,712

The annuity factor of 150.31 is how much you can borrow per £1 of monthly payment at 7% over 360 months: (1 minus 1.005833 to the power of minus 360) divided by 0.005833. It shows the lender’s logic plainly: £64.61 a month going to the Student Loans Company is £64.61 that cannot go to a mortgage, and at a stressed rate that money would have supported roughly £9,700 of borrowing.

The spread between the two approaches here is about £6,200 on the same person, same salary, same deposit. On a £38,000 salary that is the difference between offering on a £185,000 flat and having to walk away. These figures are illustrative. Real lender calculators also weigh household size, other outgoings and their own stress rates, which is why we run the case through several lenders before recommending one. For a fuller explanation of how lenders build the number, read our guide on how lenders calculate affordability, or get a quick estimate with how much can I borrow.

Do you have to declare a student loan on a mortgage application?

Yes. Every mortgage application asks for your monthly commitments, and a student loan is one of them. Leaving it off is not a clever way to borrow more. It is a fast way to get declined.

The underwriter will compare your declared outgoings against your payslips. If the payslip shows a £64 student loan deduction and the application shows nothing, the case goes back with a query at best, or is declined as a misrepresentation at worst. Worse, a lender that approved you on a figure that excluded the loan could have lent you more than you can comfortably afford, which is exactly what affordability rules are designed to stop.

Declare the plan type, the monthly amount from your latest payslip and, if you have one, the Postgraduate Loan as a separate line. If you are self-employed, your repayments are collected through Self Assessment, so the lender will see them on your SA302 tax calculation rather than a payslip. Declare the annual figure divided by 12.

Should you pay off your student loan before getting a mortgage?

For most graduates, no, and the reason is one that almost nobody explains properly: your repayment is based on your income, not your balance. Overpaying reduces what you owe, but it does not reduce the monthly deduction on your payslip by a single penny until the loan is cleared completely. The lender only sees the deduction, so a partial overpayment does nothing for your affordability.

Here is the same £10,000 of savings used two ways by the Plan 2 graduate above, buying a £200,000 home with £20,000 already saved. The mortgage rates are illustrative, not current best buys.

	Option A: overpay the student loan	Option B: add it to the deposit
Deposit	£20,000 (10%)	£30,000 (15%)
Mortgage needed	£180,000	£170,000
Illustrative rate	4.6% (90% LTV)	4.4% (85% LTV)
Monthly mortgage payment, 25 years	£1,010.74	£935.29
Student loan deduction on payslip	£64.61 (unchanged)	£64.61
Maximum borrowing	Unchanged	Unchanged, but you need £10,000 less of it

Option B is £75.45 a month cheaper on the mortgage, borrows £10,000 less, and moves you into a lower loan-to-value band with a wider choice of lenders. Option A lowers a balance that, on Plan 2, is written off 30 years after the April you were first due to repay. Many Plan 2 graduates will never clear it in full, so money used to overpay may simply reduce a debt that would have been cancelled anyway.

The exception is a small balance you can clear completely. A Plan 1 graduate on £38,000 paying £83.25 a month, with £4,000 left, removes the whole deduction by paying it off. At the 7% stress rate used above, that could free up roughly £12,500 of borrowing (£83.25 × 150.31). Clearing a loan outright can make sense; chipping at one rarely does. This is general information, not a personal recommendation, and the right answer depends on your balance, plan, salary trajectory and what else your savings need to cover.

What if you have a large balance, as a doctor or professional?

Large balances look frightening but, as the table above shows, the balance does not drive the mortgage calculation. What drives it for doctors, dentists, vets, lawyers and other long-course graduates is the combination of plans and a rising salary.

A specialty registrar on £60,000 with a Plan 2 loan and a Postgraduate Loan repays (£60,000 minus £29,385) × 9% = £229.61 a month, plus (£60,000 minus £21,000) × 6% = £195.00 a month, a total of £424.61. Capitalised at the same 7% stress rate over 30 years, that is roughly £63,800 of borrowing a lender that fully deducts the commitment would remove.

That is a serious number, and it is why professionals often feel short-changed by online calculators. The fix is not to overpay a six-figure balance. It is to use lenders that take a more generous view of professional income. Several lenders offer enhanced income multiples, sometimes up to 5.5 or 6 times income, for qualified doctors, dentists, solicitors, accountants and similar professions, and some will lend on a future contracted salary for newly qualified professionals. Those schemes can more than offset the student loan drag. See our doctor mortgage guide and our professional mortgage guide for the lenders and the qualifying rules.

How do student loans affect a joint mortgage?

On a joint application, both applicants’ student loan deductions are counted. Two graduates on Plan 2 each pay their own deduction based on their own salary, and the lender adds both to the household’s committed outgoings.

Illustrative Knox case: a first-time buyer couple in Salford came to us after a high street calculator returned less than they needed for a £230,000 terraced house. She was a teacher on £38,000 and he was a physiotherapist on £36,000, both on Plan 2. Their combined deductions were £64.61 plus £49.61, so £114.22 a month, which at a 7% stress rate is roughly £17,000 of borrowing removed under a full-commitment model. They had a 10% deposit and no other debts. We ran the case across several lenders, found one whose affordability model weighted the student loans more lightly and whose calculator returned enough for the purchase with headroom, and the case went through on a 30 year term. Details are anonymised and simplified; the pattern is common.

If you are buying with a small deposit, our 5% deposit mortgage guide explains which lenders go to 95% and how student loans interact with their tighter affordability at that level.

Why do mortgage applications with student loans get declined, and what is the fix?

Student loans rarely cause a decline on their own. They cause declines when they combine with something else or are handled badly. The patterns we see most often:

• The loan was left off the application. The payslip shows it, the application does not, and the underwriter treats it as a discrepancy. Fix: declare the exact payslip figure from day one.
• The borrowing figure came from a gross-income calculator. Many online calculators use a simple multiple and ignore deductions, so the buyer offers on a property the lender will not support. Fix: get a figure from a lender calculator that asks for commitments, before you offer.
• The Postgraduate Loan was missed. Graduates remember their undergraduate loan and forget the separate PGL deduction, which can add £85 a month or more at £38,000. Fix: check your payslip for both “SL” and “PGL” lines.
• A bonus or overtime month inflated the deduction. Student loan repayments are calculated per pay period, so a high-earning month shows a bigger deduction. Lenders sometimes use the payslip figure as if it were typical. Fix: provide three months of payslips and explain the variation, or use a lender that averages.
• The case was stretched to the maximum alongside other debt. A car finance agreement plus a credit card balance plus a student loan can push the commitment total past what a lender accepts at your income. Fix: reduce or clear other debts first, because unlike a student loan overpayment, paying off a car finance agreement removes the monthly payment entirely.
• The wrong lender for the profile. A lender that fully capitalises commitments is the wrong home for a doctor with two loans on a high salary. Fix: match the lender to the profile before the application, not after the decline.

A decline itself does not show on your credit file, but the hard credit search does, and several in a short period can make the next lender nervous. Getting the lender right first time matters more than people think.

How can you improve your affordability if you have a student loan?

You cannot switch the student loan off, but you can change almost everything around it.

• Clear other monthly debts. Paying off a car loan or card balance removes its monthly payment. That improves affordability far more than overpaying a student loan.
• Grow the deposit. A lower loan-to-value opens more lenders and lower rates, which improves stressed affordability.
• Extend the term. A 35 year term lowers the monthly mortgage payment the lender stress-tests, which can offset part of the student loan drag. It costs more interest overall, so weigh it carefully.
• Use a professional or enhanced multiple scheme if your job qualifies.
• Apply jointly where it makes sense, bearing in mind both applicants’ deductions count.
• Time a pay rise well. A rise increases your income by the full amount but your student loan deduction by only 9% of it, so affordability still goes up overall.

Our first-time buyer hub covers the rest of the process, from agreement in principle to completion.

Frequently asked questions

Does a student loan show on my credit file?

No. Income-contingent loans from the Student Loans Company are not reported to the credit reference agencies, so they do not appear on your credit file or affect your score. Lenders see the repayment on your payslip or, if you are self-employed, on your SA302, and they must be declared on the application.

Does a student loan affect how much I can borrow for a mortgage?

Yes. Most lenders treat the monthly repayment as a committed outgoing, which reduces your maximum loan. For a Plan 2 graduate on £38,000, the deduction is £64.61 a month, which can reduce borrowing by roughly £3,500 to £9,700 depending on how the lender weights it.

How does a Plan 2 student loan affect a mortgage?

You repay 9% of income above £29,385 in 2026/27, and that monthly deduction reduces affordability. At £38,000 it is £64.61 a month; at £50,000 it is £154.61. The threshold is frozen from April 2027 until April 2030, so the deduction will rise with future pay rises.

Should I pay off my student loan before applying for a mortgage?

Usually not. Your repayment is set by your income, not your balance, so a partial overpayment does not change the deduction lenders see. Putting the money into your deposit usually does more. Clearing a small remaining balance completely is the exception, because that removes the deduction entirely.

Do lenders look at my student loan balance?

Rarely in any meaningful way. The balance is not on your credit file and the repayment does not depend on it. Lenders focus on the monthly deduction. A graduate owing £70,000 and one owing £20,000 on the same plan and salary are assessed the same way.

Does a Postgraduate Loan affect a mortgage differently?

It is assessed the same way but adds a second deduction: 6% of income above £21,000. Combined with Plan 2 at a £38,000 salary, the total is £149.61 a month, more than double the Plan 2 deduction alone. Make sure both appear on your application.

Can I get a mortgage with a student loan as a doctor?

Yes. Doctors often carry Plan 2 and Postgraduate Loans with large balances, but lenders focus on the monthly deduction. Professional mortgage schemes with enhanced income multiples, and lenders that accept future contracted salaries, often more than offset the student loan effect.

Do both applicants’ student loans count on a joint mortgage?

Yes. Each applicant’s deduction is based on their own salary and plan, and the lender adds both to the household’s outgoings. Two Plan 2 graduates on £38,000 and £36,000 pay £114.22 a month between them, which the lender will factor in.

Speak to Knox about a mortgage with a student loan

The student loan is the easy part of your application to plan around once you know the real deduction and which lenders weigh it lightly. We are a whole-of-market broker, we check your payslip figures before any credit search, and we match you to a lender whose affordability model fits your plan and profession. Book a free, no-obligation discovery call and we will tell you what you can realistically borrow.

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