If you’re saving to buy a home in the UK, the first number you need to know is 5%. That’s the minimum deposit most lenders will accept for a residential mortgage in 2025. On an average UK property costing roughly £299,892, that works out at about £15,000. But here’s the catch: putting down just 5% locks you into higher interest rates and stricter affordability checks. I’ve watched this pattern play out for years, and the single biggest mistake I see is people focusing only on the deposit amount while ignoring the thousands in extra costs that arrive on day one.
That last figure is the one that catches people out. On top of your deposit, you’ll need another £3,000 to £8,000 in liquid cash for solicitor fees, surveys, stamp duty, and moving costs. I’ve seen buyers scrape together a 5% deposit only to realise they’re short by thousands when the completion date arrives. The trick isn’t just hitting the deposit number — it’s knowing what else is coming and planning for it now. Here’s what you actually need to know.
What a down payment actually is and why the size matters
A down payment — or deposit — is the portion of the purchase price you pay from your own savings rather than borrowing. The rest comes from your mortgage. The size of your deposit determines your loan-to-value ratio (LTV), which is the percentage of the property’s value you’re borrowing. A 5% deposit means a 95% LTV. A 10% deposit means 90% LTV. And here’s where it gets practical: lenders price their deals around these bands. Jumping from 95% LTV to 90% LTV typically unlocks substantially cheaper interest rates. I’ve run the numbers for dozens of scenarios, and the difference often works out to hundreds of pounds a month.
Lenders also cap how much they’ll lend based on your income. Most will let you borrow up to 4.5 times your annual salary. So if you earn £40,000, the maximum mortgage is around £180,000. Add your deposit, and that gives you your maximum purchase price. If you’re self-employed, the bar is higher — lenders often want 2–3 years of accounts (SA302s) to verify your income. Some use a day-rate formula instead: annual income equals your day rate multiplied by 5 days multiplied by 46 weeks. It’s worth knowing which approach your lender uses before you apply.
Why your deposit size changes everything about your purchase
The difference between a 5% and a 10% deposit isn’t just about the cash you hand over. It affects the interest rate you’re offered, the monthly payment you’ll make, and the total cost of your mortgage over its lifetime. According to MortgageMapper, saving an additional 5% (reaching a 10% deposit) can save a buyer nearly £9,000 in interest over five years. That’s real money — roughly £150 a month that stays in your pocket instead of going to the bank.
Regional differences make this even starker. In the North East, a 5% deposit might be £8,000. In London, the same 5% could be £28,000. And to buy an average London home with a 5% deposit, a household needs an income of nearly £120,000. If you’re buying outside the South East, the numbers are far more manageable. What I’d do in your shoes: work out the 10% deposit figure for your target area first, then see if you can stretch to it. The long-term savings are hard to ignore.
Where buyers get tripped up on deposits
Ignoring the hidden costs until it’s too late
The most common mistake I see is buyers treating the deposit as the only upfront cost. It’s not. On top of your deposit, you need to budget for stamp duty, solicitor fees (£1,000–£2,000), surveys (£400–£600), mortgage arrangement fees (£0–£2,000), and removal costs. That’s £3,000 to £8,000 in additional cash that has nothing to do with your deposit. I’ve seen buyers scrape together a 5% deposit only to discover they’re £5,000 short on completion day because they forgot about stamp duty. The fix is simple: build a separate savings pot for these costs before you start house hunting.
Overlooking the April 2025 stamp duty change
On April 1, 2025, the tax-free threshold for first-time buyers drops from £425,000 to £300,000. If you’re buying a £400,000 home after that date, you’ll face a £5,000 stamp duty bill that would have been £0 before. That’s a significant chunk of cash that needs to be in your account on day one. If you’re close to exchanging contracts, timing matters enormously. Completing before April 1 could save you thousands.
Not using the Lifetime ISA bonus
The Lifetime ISA (LISA) gives you a 25% government bonus on your savings, up to £1,000 per year. That’s a risk-free return you can’t get anywhere else. If you save £4,000 in a LISA, the government adds £1,000. Over a few years, that bonus can make the difference between a 5% and a 10% deposit. The catch: you can only use it for your first home (under £450,000) or retirement, and you need to have the account open for at least 12 months before you use the money. If you’re planning to buy in the next year, open one now.
Assuming self-employment won’t be an issue
If you’re self-employed, lenders treat you differently. They typically want 2–3 years of accounts (SA302s) to verify your income. Some use a day-rate formula: annual income equals your day rate multiplied by 5 days multiplied by 46 weeks. If you’ve been self-employed for less than two years, your options are limited. My advice: get your accounts in order early, and consider speaking to a mortgage broker who specialises in self-employed cases. They’ll know which lenders use the day-rate formula and which don’t.
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| Deposit Size | LTV Ratio | Typical Interest Rate Impact |
|---|---|---|
| 5% | 95% LTV | Highest rates, strictest affordability checks |
| 10% | 90% LTV | Substantially cheaper deals than 95% LTV |
| 20% | 80% LTV | Best mainstream rates available |
| 25%+ | 75% LTV or lower | Premium rates, often reserved for buy-to-let or high-value purchases |
How to build your deposit and choose the right strategy
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Use a Lifetime ISA to get a 25% boost
The LISA is the single best savings tool for first-time buyers. You can save up to £4,000 per year, and the government adds 25% — that’s up to £1,000 free money annually. The money must be used for your first home (under £450,000) or left until retirement. You need the account open for at least 12 months before you can use it, so open one as soon as you decide to buy. If you’re self-employed, the LISA works the same way — your bonus is based on what you save, not your income type. A Lifetime ISA guide book can walk you through the rules and help you avoid the withdrawal penalties.
Consider government schemes that reduce your deposit
The Mortgage Guarantee Scheme is now permanent, meaning the government guarantees the portion of your mortgage above 80% LTV. This lets you buy with a 5% deposit on properties up to £600,000. The First Homes Scheme offers a 30% to 50% discount on new-build homes for first-time buyers and key workers. Your 5% deposit is calculated on the discounted price, which significantly lowers the cash required. Shared Ownership lets you buy a share of a property (typically 25%) and pay rent on the rest. You only need a 5% deposit on the share you buy, not the full property value. If you’re struggling to save a full deposit, these schemes are worth exploring.
Look into zero-deposit and new-build options
The Skipton Track Record Mortgage is a rare but real option: if you can prove 12 months of consecutive rental payments and have a clean credit history, you can borrow 100% of the property value with £0 deposit. For new builds, the Deposit Unlock scheme lets you buy with just a 5% deposit, and the Own New Rate Reducer sees builders contribute 3% to 5% of the purchase price to subsidise your mortgage interest rate — potentially reducing it to between 0.5% and 2% for the first few years. These options aren’t widely advertised, so you need to ask specifically about them when you speak to lenders or developers.
Plan for the full timeline from offer to completion
From application to mortgage offer typically takes two to six weeks, depending on how quickly you provide documentation. Conveyancing takes another six to twelve weeks. Budget for three to four months from accepted offer to completion. During that time, your deposit needs to be accessible — not tied up in notice accounts or investments. If you’re using a LISA, make sure you instruct your solicitor early, as the withdrawal process takes time. A UK home buying checklist can help you track every step and deadline so nothing slips.
- 1Open a Lifetime ISADeposit up to £4,000 per year and get a 25% government bonus. Must be open 12 months before use. Only for first homes under £450,000.
- 2Calculate your target deposit and hidden costsAim for 10% if possible. Add £3,000–£8,000 for stamp duty, solicitor fees, surveys, and moving costs. Build a separate savings pot for these.
- 3Check government scheme eligibilityMortgage Guarantee Scheme (5% deposit, properties up to £600k), First Homes Scheme (30–50% discount on new builds), Shared Ownership (buy a 25% share).
- 4Get a mortgage agreement in principleThis shows sellers you’re serious. Lenders will check your income, outgoings, and credit history. Self-employed buyers need 2–3 years of SA302s ready.
- 5Budget 3–4 months from offer to completionMortgage offer takes 2–6 weeks. Conveyancing takes 6–12 weeks. Keep your deposit accessible and your paperwork organised throughout.
Frequently asked questions about UK house deposits
Can I use a credit card to pay my deposit? ▾
What happens if I can’t complete on time and lose my deposit? ▾
Can I use a gifted deposit from family? ▾
Do I need a deposit for a buy-to-let mortgage? ▾
What if I’ve been self-employed for less than two years? ▾
Is a 5% deposit always the cheapest option? ▾
Your next move
The single most important thing you can do today is open a Lifetime ISA if you haven’t already. That 25% government bonus is free money that directly boosts your deposit. Then work out your target deposit — aim for 10% if you can — and build a separate savings pot for the £3,000 to £8,000 in hidden costs. The difference between a rushed 5% deposit and a planned 10% deposit is roughly £9,000 in your pocket over five years. That’s worth the extra few months of saving. If this was useful, you might also want to read Stop Dreaming, Start Owning: Your 5-Step UK Home Buying Game Plan.
Sources and Further Reading
Tips for buying a house in the UK without breaking the bank — Practical strategies for keeping costs down throughout the buying process.
Don’t just buy a home — build equity: smart UK investment strategies — How to think about your home purchase as a long-term wealth-building tool.
What is the minimum down payment deposit for a house in the UK 2026?. MortgageMapper, 2025.
How much deposit on a house?. Envelop Finance, 2025.
Financing a house purchase. Money Saving Advice, 2025.
