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£400k mortgage monthly payments over 25 years come to about £1,897 at an example 3% rate, £2,111 at 4% and £2,338 at 5%, on a repayment basis. Interest only at an example 4% is £1,333 a month. All of these are illustrations rather than quotes, because the real figure depends on the rate a lender offers you.
At £400,000 the stamp duty picture changes more than the payments do. Depending on the deposit, the house price lands either side of £500,000, which is where first time buyer relief stops. The deposit table further down shows where that happens.
£400k mortgage repayments at different example rates
The table below is a £400,000 loan over 25 years. Moving from an example 4% to 5% adds about £227 a month on repayment and £334 a month on interest only. Over the full term, that one point of rate is worth about £68,104 on repayment.
| Example rate | Repayment, per month | Total repaid over 25 years | Interest only, per month |
|---|---|---|---|
| 3% | £1,897 | £569,054 | £1,000 |
| 4% | £2,111 | £633,404 | £1,333 |
| 5% | £2,338 | £701,508 | £1,667 |
| 6% | £2,577 | £773,162 | £2,000 |
Illustration only. These figures are worked out on a £400,000 mortgage at the example interest rates shown, with the rate staying the same for the whole term and payments made monthly. They are not a quote, not an offer of credit and not the rates lenders are offering today. They leave out product fees, valuation and legal costs, and any change in rate when a fixed or tracker period ends, so your actual payments and the total you repay will be different. The rate you are offered depends on the lender, your deposit, your income, your credit history and the product you choose. Figures are rounded to the nearest pound. On interest only the monthly payment covers the interest alone, so the full loan is still owed at the end of the term and you need a way of repaying it that the lender accepts. Your home may be repossessed if you do not keep up repayments on your mortgage.
How a longer term changes the repayments
Spreading £400,000 over 30 or 35 years brings the monthly figure down, and the cost is more interest over the life of the loan. At an example 5%, the payment falls from £2,338 over 25 years to £2,019 over 35 years, and the total repaid goes from about £701,508 to £847,875. The longest term a lender allows depends partly on your age when the mortgage would end.
| Term | At an example 4% | At an example 5% |
|---|---|---|
| 25 years | £2,111 | £2,338 |
| 30 years | £1,910 | £2,147 |
| 35 years | £1,771 | £2,019 |
Illustration only. These figures are worked out on a £400,000 mortgage at the example interest rates shown, with the rate staying the same for the whole term and payments made monthly. They are not a quote, not an offer of credit and not the rates lenders are offering today. They leave out product fees, valuation and legal costs, and any change in rate when a fixed or tracker period ends, so your actual payments and the total you repay will be different. The rate you are offered depends on the lender, your deposit, your income, your credit history and the product you choose. Figures are rounded to the nearest pound. On interest only the monthly payment covers the interest alone, so the full loan is still owed at the end of the term and you need a way of repaying it that the lender accepts. Your home may be repossessed if you do not keep up repayments on your mortgage.
A £400,000 repayment mortgage over 25 years is about £2,111 a month at an example 4%, or £2,338 at 5%.
At 4.5 to 5.5 times income, the usual range across my panel, £400,000 needs about £72,727 to £88,889 a year.
With a 25% deposit the price is about £533,300, over the £500,000 limit for first time buyer relief.
What salary do you need for a £400k mortgage?
Income multiples are the starting point. Across my panel the usual accepted range is 4.5 to 5.5 times income, so £400,000 means income of roughly £72,727 at 5.5 times and £88,889 at 4.5 times. I have placed a case at 6 times income, where the figure would be £66,667, though that was one lender’s view of one application.
Two incomes can be added together. What a lender takes off before applying a multiple matters just as much: existing loans, car finance, card balances, maintenance and childcare all reduce the amount. Each lender does this its own way, so the answer is lender by lender.
| Income multiple | Income needed (single or joint) |
|---|---|
| 4.5 times | £88,889 |
| 5 times | £80,000 |
| 5.5 times | £72,727 |
| 6 times | £66,667 |
How much deposit and stamp duty on a £400k mortgage?
This table starts from the £400,000 loan and works out the house price for each deposit. A 10% deposit means a price of about £444,400, 15% means £470,600, and 25% takes it to £533,300.
| Deposit | House price | Deposit amount | Stamp duty, home mover | Stamp duty, first time buyer |
|---|---|---|---|---|
| 10% | £444,400 | £44,400 | £12,220 | £7,220 |
| 15% | £470,600 | £70,600 | £13,530 | £8,530 |
| 25% | £533,300 | £133,300 | £16,665 | No relief (price over £500,000) |
Stamp duty figures use the rates for England and Northern Ireland that apply from 1 April 2025, checked in September 2026, for a main home. Buying an additional property adds a 5% surcharge on top. Scotland and Wales have their own taxes and bands. House prices are rounded to the nearest £100. Your solicitor confirms the exact figure.
The £500,000 first time buyer line
First time buyer relief applies to prices up to £500,000. With a 10% or 15% deposit on £400,000 of borrowing, the price sits below that, and a first time buyer pays £7,220 or £8,530 against £12,220 or £13,530 for a home mover. With a 25% deposit the price is £533,300, and the relief is lost entirely rather than tapered, so a first time buyer pays the full £16,665, the same as a home mover.
So for a first time buyer at this loan size, the price of the house matters to the tax bill as much as the size of the mortgage. Whether you qualify, and the exact figure, is for your solicitor to confirm, and wider tax questions are for your solicitor or accountant.
Home movers borrowing £400,000
Home movers pay the standard rates whatever the deposit. The deposit usually comes from the equity in the home being sold, so the sale price and what is left on the current mortgage set how much can go in. If you are part way through a fixed rate, any early repayment charge and whether the current product can be moved to the new property (porting) are part of the sums.
Speak to an expert
Looking at £400,000? Tell me your income, deposit and the price range you are looking at, and I will show you the monthly figures and the stamp duty, lender by lender.
Repayment, interest only or part and part?
A repayment mortgage clears the loan by the end of the term, because every payment includes some of the balance as well as the interest. Interest only keeps the monthly figure lower, as the first table shows, but the whole £400,000 is still owed when the term ends. Part and part puts some of the loan on each basis, so the payment and the balance left at the end both sit in between.
For a residential interest only mortgage, lenders ask for a repayment method, evidence that your earnings continue into retirement, or both. My interest only mortgages page explains what they look for.
For the loan sizes either side, see my breakdowns of £300k mortgage monthly payments and £500k mortgage monthly payments. Larger loans are covered on my page about high value mortgages in Hampshire.
Which figures apply to you?
None of the tables tells you which term, deposit or repayment method is right, because that depends on your income, your plans and which trade-offs you are comfortable with. Working that out is what an advice appointment is for, and the decision stays yours. My fee is a flat £350, payable on mortgage offer, and I work with more than 120 lenders. In my recent cases offers have typically come through in under two weeks, though timescales vary.
You can call me on 01425 203055 or book a 15 minute call.
Need Personal Mortgage Advice?
Every buyer’s situation is different. While this guide explains the general rules, the right mortgage for you depends on your income, deposit, credit history and future plans. If you’d like tailored advice, I can help, with 120+ lenders to choose from.
