What is a house deposit?
A deposit is the share of the purchase price you pay yourself. The figure lenders quote is your loan-to-value (LTV), the size of the mortgage as a percentage of the price. A 10% deposit means a 90% LTV mortgage.
The bigger your deposit, the lower your LTV, and the lower the interest rate lenders will usually offer. Rates step down at 90%, 85%, 80%, 75% and 60% LTV, so even a slightly larger deposit can cut your monthly payment.
Deposit size by purchase price
What different deposit percentages look like in cash at common UK price points.
| Purchase price | 5% deposit | 10% deposit | 15% deposit | 20% deposit |
|---|---|---|---|---|
| £150,000 | £7,500 | £15,000 | £22,500 | £30,000 |
| £200,000 | £10,000 | £20,000 | £30,000 | £40,000 |
| £250,000 | £12,500 | £25,000 | £37,500 | £50,000 |
| £300,000 | £15,000 | £30,000 | £45,000 | £60,000 |
| £400,000 | £20,000 | £40,000 | £60,000 | £80,000 |
| £500,000 | £25,000 | £50,000 | £75,000 | £100,000 |
What your LTV means for your mortgage
The deposit you put down sets your loan-to-value, which drives the rate and choice you'll be offered.
| Deposit | Loan-to-value | Typical rate access | Product choice |
|---|---|---|---|
| 5% | 95% LTV | Highest mainstream rates | Limited |
| 10% | 90% LTV | Noticeably better | Wide |
| 15% | 85% LTV | Competitive | Very wide |
| 25% | 75% LTV | Among the lowest | Full market |
| 40%+ | 60% LTV | Best available | Full market |
What each deposit size gets you
- 5% (95% LTV): the practical minimum for most first-time buyers. Mortgages exist but rates are the highest and choice is narrower.
- 10% (90% LTV): a meaningful drop in rate and far more products to choose from.
- 15% (85% LTV): a sweet spot for many movers, competitive rates without needing a huge sum.
- 20 to 25% (80 to 75% LTV): access to the lowest mainstream rates and the lowest monthly payments.
- 40%+ (60% LTV): the very best rates; common for downsizers and those with equity.
How to work out the deposit you need
Size your deposit around the full cash picture, not just the headline percentage.
Set a realistic price range
Use a mortgage agreement in principle to understand how much you can borrow, then work back to the price you can target.
Total your other buying costs
Add up stamp duty, conveyancing, a survey, mortgage fees and removals. This is cash that cannot go into the deposit.
Keep an emergency fund
Set aside three to six months of essential outgoings to keep after completion, plus a small repairs buffer.
Put the rest towards the deposit
Whatever remains is your deposit. Aim to land on a clean LTV band such as 90% or 85% to unlock better rates.
Don't drain your savings into the deposit
The deposit is not the only cash you need. Stamp duty, conveyancing, a survey, mortgage fees and removals all fall due around completion, and you should keep an emergency fund afterwards. Work out the full cash figure before deciding how much to put down.
How much should you actually put down?
If you can comfortably reach 10 to 15% without using money you need for buying costs or your emergency fund, that is usually the right balance: it lowers your rate without leaving you cash-poor on day one.
Putting down more reduces your monthly payment and total interest, but tying up every spare pound is risky, a new home brings immediate costs and the occasional surprise. Keep a reserve.