How Much Deposit Do First-Time Buyers Need in London?

The deposit is the wall between renting and owning in London. On a £400,000 flat, the difference between a 5% and a 15% deposit is £40,000 in cash — years of saving — plus thousands in interest and fees. How much do first-time buyers actually need in London in 2026? The answer depends on the price you target, the mortgage you want, and how cleverly you save. Here is the full breakdown.

The minimum: 5% deposits

The absolute minimum most lenders accept is 5%. On a £350,000 one-bed, that is £17,500; on a £450,000 two-bed, £22,500. Five per cent deals exist — some lenders have kept them alive through 2026 — but they come with strings: higher interest rates (often 0.5–1% above 10% deposit deals), stricter affordability checks, fewer lenders to choose from, and greater risk of negative equity if prices dip.

Five per cent also means the thinnest margin for error. A 5% price fall wipes your equity entirely, trapping you if you need to sell or remortgage unexpectedly. It is a viable route — thousands of Londoners buy this way every year — but go in understanding the trade-offs, not just the lower savings target.

The sweet spots: 10% and 15%

Ten per cent is where the market opens up properly. On £350,000–£450,000 purchases, that is £35,000–£45,000 — a serious but achievable target for dual-income households prepared to save hard. Lender choice expands dramatically, rates improve meaningfully, and you have a buffer against small price falls. Most first-time buyer activity in London clusters here.

Fifteen per cent (£52,500–£67,500) is the next meaningful threshold: access to the best mainstream rates, comfortable equity buffer, and monthly payments that drop noticeably. The jump from 10% to 15% saves roughly £100–£150 a month on a typical London mortgage — £18,000+ over a decade. If you can stretch to 15% without raiding your emergency fund, the long-term maths usually favours it.

Beyond 15%, the rate improvements diminish — 20% and 25% deposits get marginally better deals, but the opportunity cost of saving the extra £20,000+ (years of renting while you save) often outweighs the benefit. Our monthly savings guide helps model how long each tier takes on your income.

The forgotten costs: deposit plus £10,000–£15,000

The deposit is not the total cash you need. On a £400,000 first purchase, budget on top: stamp duty (£7,500 at current first-time buyer thresholds — verify on gov.uk as thresholds move), solicitor fees (£1,500–£2,500), survey (£400–£800), mortgage fees (£0–£2,000), and moving costs (£500–£1,500). That is £10,000–£14,000 before you have bought a single curtain.

Then the post-move float: furniture, immediate repairs, and — critically — an emergency fund. Buying with zero savings beyond the deposit is how boiler breakdowns become credit-card debt. Keep 3–6 months of expenses separate, always. Our guide to starting an emergency fund from scratch is essential pre-purchase reading.

How to save the deposit faster

The Lifetime ISA: free money

The single best deposit-saving tool in Britain: save £4,000 a year into a Lifetime ISA and the government adds £1,000 — a 25% instant return no investment can match. Two first-time buyers get £2,000 a year of free money. Use a stocks-and-shares LISA if your timeline is 5+ years, cash LISA if sooner. The £450,000 property price cap applies UK-wide — fine for most London flats, tight for houses.

Automate and separate

Open a dedicated deposit savings account — ideally the best-paying easy-access account you can find — and automate transfers on payday. Money you never see, you never spend. The 50/30/20 budget framework gives structure: many successful deposit-savers run 50/20/30 (needs/savings/wants) during the saving years.

Boost income temporarily

The deposit sprint rewards temporary intensity: a year of flatsharing instead of solo renting (£400+ a month saved), a side hustle directed entirely at the deposit, selling the car if transport allows. A £500-a-month boost cuts a £40,000 target from 80 months to 40. It is miserable and it works.

Help that exists (beyond parents)

The Bank of Mum and Dad funds a huge share of London deposits — but it is not the only help. Shared ownership cuts the deposit to 5–10% of the share (from £5,000–£10,000 in many cases). The First Homes scheme discounts new-builds 30–50%. Some employers offer deposit loans or salary-advance schemes. And guarantor mortgages let family back your borrowing without gifting cash.

If family help is available, structure it properly: gifted deposits need a gifted-deposit letter for the lender; loans from family complicate affordability checks. Get the paperwork right — lenders reject applications over sloppy gift documentation regularly. The MoneyHelper first-time buyer guides cover the schemes in detail.

How long will it take?

The honest maths for a single London earner on £40,000 saving £600 a month: £35,000 takes nearly 5 years (with interest and LISA bonuses, closer to 4). A couple on £70,000 combined saving £1,200 a month: £45,000 in about 3 years. These timelines are why the “just save harder” advice rings hollow — the structural answer involves earning more, spending less on rent (flatshare), or buying cheaper (outer zones, shared ownership).

Do not let the perfect deposit delay you indefinitely. Renting for an extra two years to go from 10% to 15% costs £40,000+ in rent — often more than the interest saved. There is a point where buying with 10% beats waiting for 15%, and most buyers cross it sooner than they think. Track your progress visibly — a simple spreadsheet showing the deposit growing month by month keeps motivation alive through the long middle stretch when the target still feels distant.

Conclusion

First-time buyers in London in 2026 need 5% minimum (£17,500–£22,500 on typical flats), 10% for real choice (£35,000–£45,000), and 15% for the best rates (£52,500–£67,500) — plus £10,000–£14,000 for stamp duty, fees and moving, and an untouched emergency fund on top. Maximise the Lifetime ISA, automate savings into top-paying accounts, consider shared ownership and properly-structured family help, and do not over-save: the rent you pay while chasing the perfect deposit is a cost too, and buying with 10% today often beats waiting years for 15%.

Frequently Asked Questions

Can I buy in London with a 5% deposit?

Yes — 5% mortgages exist, requiring £17,500–£22,500 on typical London flats. Expect higher rates, fewer lenders and stricter checks than 10%+ deals, plus greater negative-equity risk if prices fall. Get a mortgage agreement in principle before house-hunting.

How much deposit for a £400,000 flat in London?

£20,000 at 5%, £40,000 at 10%, £60,000 at 15% — plus £10,000–£14,000 for stamp duty, solicitor, survey and moving costs. Budget the total cash, not just the deposit.

Is the Lifetime ISA worth it for a house deposit?

Almost always yes: the 25% government bonus (£1,000 a year on £4,000 saved) is the best risk-free return available. Two buyers get £2,000 a year combined. Watch the £450,000 property cap and the early-withdrawal penalty (25%, which claws back more than the bonus).

How long does it take to save a London deposit?

Typically 3–5 years: a couple saving £1,200 a month reaches £45,000 in about 3 years; a single saver at £600 a month needs 4–5 years for £35,000. Lifetime ISA bonuses and compound interest shorten this — and flatsharing during the sprint can cut a year off.