By Hamid Ali, MSc Accounting & Finance, ACCA in progress, Founder of DebtShift | Updated July 2026
What Is a Debt-to-Income Ratio UK? (2026)
What it is · How to calculate it · What UK lenders actually want to see
You can have a good credit score, a clean payment history, and still get turned down for a mortgage. The number that kills more applications than any other isn’t your credit score. It’s your debt-to-income ratio.
Most people have never heard of it. Lenders look at it before almost anything else.
What is a debt-to-income ratio?
Your debt-to-income ratio — DTI — is the percentage of your gross monthly income that goes toward paying debts. It’s a single number that tells a lender how much of your income is already spoken for before you take on anything new.
The formula is simple:
(Total monthly debt payments ÷ Gross monthly income) × 100
Use gross income — before tax, before pension contributions
If you earn £3,000 a month before tax and your total debt payments are £750 a month, your DTI is 25%. That’s considered healthy. If those payments were £1,500 a month, your DTI is 50%. That’s where lenders start getting uncomfortable.
Check yours right now using our DTI Calculator — it takes 60 seconds and shows exactly where you stand.
Calculate your DTI now
Enter your income and monthly debts. Get your ratio instantly — and see what UK lenders will make of it.
Check My DTI →What counts as debt in the calculation
This is where most people get it wrong. DTI isn’t just your credit cards. Lenders include everything that’s a regular monthly obligation.
Included in your DTI:
- Mortgage or rent payments
- Credit card minimum payments
- Personal loan repayments
- Car finance or car loan payments
- Student loan repayments (based on your current monthly deduction)
- Overdraft repayment arrangements
- Child maintenance or support payments
- Any other regular debt repayment
Not included in DTI:
- Grocery shopping
- Utility bills (gas, electric, water)
- Subscriptions (Netflix, gym, phone)
- Council tax (treated as essential expenditure, not debt — unless you have council tax arrears)
- Insurance premiums
One thing catches people out on income: use your gross figure — before tax, before pension contributions. If your salary is £36,000 a year, your gross monthly income for DTI purposes is £3,000, not your take-home pay.
Also include all income sources: salary, bonuses (typically averaged), benefits, rental income, child benefit, any regular freelance earnings.
What UK lenders actually want to see
UK lenders don’t publish a single universal DTI limit — each sets its own threshold based on their risk appetite and the type of lending. But the general picture is consistent across the market.
| DTI Range | How Lenders View It |
|---|---|
| Under 20% | Excellent — all lenders will consider you |
| 20%–29% | Good — almost all lenders happy to proceed |
| 30%–39% | Acceptable — most lenders proceed at standard terms |
| 40%–49% | Moderate risk — specialist lenders, good credit history needed |
| 50%–74% | High risk — limited lenders, less favourable terms |
| 75%+ | Very high risk — most lenders will decline |
The FCA regulates how UK mortgage lenders assess affordability under the Mortgage Conduct of Business rules (MCOB). The broad consensus across the market is that below 40% is where most mainstream lenders are comfortable. Above 40% doesn’t automatically mean rejection — but it means your application gets more scrutiny and your options narrow.
Some lenders — including Leek United Building Society, Foundation Home Loans, and Metro Bank — don’t have a fixed DTI cap at all. They assess applications holistically. A mortgage broker can tell you which lenders fit your specific situation without burning a hard search to find out.
Why DTI matters more than your credit score
Your credit score shows your history — whether you’ve paid on time, how long you’ve had accounts, how much credit you’ve used. It’s a backward-looking measure.
Your DTI shows your present — right now, today, how much of your income is already gone before you make a single mortgage payment. Lenders care about the future. They want to know if you can afford what you’re asking for, not just whether you’ve been responsible in the past.
Someone with a 750 credit score and a 55% DTI is a higher lending risk than someone with a 650 score and a 22% DTI. The score tells one story. The DTI tells a different one.
DTI also doesn’t affect your credit score. The credit reference agencies — Experian, Equifax, TransUnion — don’t know your income, so they can’t calculate DTI. It’s calculated by the lender directly from your application. Which means improving it doesn’t require waiting for credit file updates — it responds to changes in your actual debt and income immediately.
What’s a realistic example of how DTI is calculated?
Take someone earning £46,000 a year (£3,833/month gross). Their monthly debt payments are:
- Proposed mortgage: £800
- Credit card minimum: £160
- Car finance: £310
- Overdraft repayment: £85
Total monthly debt: £1,355
DTI: £1,355 ÷ £3,833 × 100 = 35.4%
That sits in the “acceptable” band — most lenders would consider this application at standard terms. If they could reduce the car finance or credit card, they’d move into the “good” band and potentially access better rates.
Does my student loan count toward my DTI?
Yes — UK mortgage lenders typically include your current student loan repayment in your DTI calculation. The figure they use is your actual monthly deduction, not the total outstanding balance.
For Plan 2 loans, the repayment threshold rose to £29,385 a year from April 2026 (frozen at that level for three years after that), and you repay 9% of income above that threshold. So on a £35,000 salary, you’d be repaying roughly £42/month — which gets included in your DTI. It’s not a massive number but it’s there.
The income-contingent nature of UK student loans means lenders understand repayments change with income, but they still include current payments in affordability assessments.
My DTI is high. Can I still get a mortgage?
Possibly — but it depends on how high and what else is on your application. A DTI between 40–50% doesn’t automatically mean rejection. Specialist and adverse credit lenders operate across a wider range of DTI thresholds than high street lenders.
What helps offset a high DTI: a large deposit, a strong credit history, stable long-term employment, and significant savings. A whole-of-market mortgage broker can tell you which lenders’ criteria you actually fit without you having to apply blind and burn a hard search finding out.
The best thing you can do before applying is use our DTI Calculator to know your exact number, then work on reducing it before you approach lenders.
How do I lower my DTI?
Two levers: reduce debt or increase income. In practice, reducing debt is faster and more reliable.
Fastest wins: Pay off a small loan entirely — removes its monthly payment from your DTI completely. Pay down credit card balances — reduces minimum payment obligations. Avoid taking on any new debt in the 3–6 months before a mortgage application.
Slower but significant: Clear a car finance agreement if it’s near the end of its term. Consolidate multiple high-minimum debts into one lower-payment loan (carefully — check the total interest cost). Increase income through a pay rise, additional employment, or rental income.
Every £100 you remove from monthly debt payments drops your DTI by roughly 2–3 percentage points on an average UK salary. Small changes compound quickly.
The number most people don’t know they have
The vast majority of people in the UK have never calculated their DTI. They know roughly what they earn and roughly what they owe, but they’ve never looked at the relationship between the two as a single percentage.
That number follows you into every significant financial decision — mortgage, car finance, personal loan, even some credit cards. Knowing it before a lender does gives you the ability to act on it.
Calculate yours now. If it’s already in a good range, great — you know where you stand. If it’s higher than you’d like, you have time to change it before it matters.
Also worth reading: How to Pay Off Debt — the strategies that reduce your DTI fastest while saving the most in interest.
Find out your DTI in 60 seconds
Enter your numbers into our free DTI Calculator. See your ratio, what it means, and what to do about it.
Calculate My DTI →If you’re struggling with debt and the numbers feel overwhelming, free help is available from StepChange (0800 138 1111) — a debt advice charity authorised by the FCA for debt counselling — and MoneyHelper (0800 138 7777), a free, government-backed money guidance service. Both are free and confidential.
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