Take a £300,000 property. A 5% deposit means finding £15,000. A 25% deposit means finding £75,000 — five times as much, for a mortgage that's only slightly smaller. The gap in cash required is dramatic; the gap in what lenders will actually offer you is arguably even more important.
What the bands actually look like
On that same £300,000 house: 5% down is £15,000 (a £285,000 mortgage), 10% is £30,000 (£270,000 mortgage), 15% is £45,000, 25% is £75,000, and 40%+ is £120,000 or more. Lenders group these into LTV (loan-to-value) bands, and pricing shifts at each one — 95% LTV is the entry point most mainstream lenders will accept, often through dedicated first-time buyer routes. 90% LTV opens up a noticeably wider lender pool with better rates. Every band above that improves incrementally, and once you're at 60% LTV or below, you're generally looking at the best rates the market has to offer.
Why crossing an LTV line matters more than the deposit size alone
A 95% LTV borrower is a bigger risk to a lender than a 60% LTV borrower — there's simply less equity cushion if property prices dip. That's why the rate gap between a 5% deposit and a 25% deposit can run a full percentage point or more, not just a rounding difference. On a mortgage, a full point compounds into serious money over 25-30 years.
Schemes exist, but check what's current
Various government and lender-backed programs specifically target first-time buyers stuck at the smaller-deposit end, since the 95% LTV segment is thinner and less competitive than the rest of the market. What's actually on offer shifts over time — don't assume a scheme you read about a year or two ago still exists in the same form.
The deposit is not the whole bill
Stamp Duty Land Tax (above the relevant threshold), legal and conveyancing fees, mortgage arrangement fees, survey costs, and the actual cost of moving all add to what you need in cash at completion. A lot of first-time buyers budget for the deposit and stop there, then get a rude surprise a few weeks before completion.
The Lifetime ISA — and its coming replacement
A Lifetime ISA adds a 25% government bonus on contributions up to £4,000 a year, specifically for a first home or retirement — genuinely free money on top of whatever you're saving yourself, subject to property price caps and other rules. Worth knowing before you rely on it long-term: the government has confirmed the LISA will be replaced by a new, simpler first-time-buyer product from April 2028, following a consultation that opened in early 2026. If a LISA is part of your deposit plan, keep an eye on how that transition actually plays out.
See what stamp duty you'd owe on top of your deposit with the Stamp Duty Calculator, and model your mortgage payment at different deposit sizes with the Mortgage Calculator.
A few things people actually ask
What's the minimum deposit for a UK mortgage?
5% is the minimum most mainstream lenders will accept (95% LTV), often through dedicated first-time buyer routes — though rates at this level are generally the least competitive in the market.
Is the Lifetime ISA being discontinued?
Yes — the government has confirmed it will be replaced by a new, simpler first-time-buyer product from April 2028, following a consultation opened in early 2026.
What other costs should I budget for beyond the deposit?
Stamp Duty (above the relevant threshold), legal and conveyancing fees, mortgage arrangement fees, survey costs, and moving costs all add to what you need at completion — a common budgeting gap for first-time buyers.