How Much House Deposit Do You Need? A UK Guide

For most people in their 20s and 30s, saving for a house deposit is the biggest financial challenge they face. The good news: you have more options than any previous generation — from 5% deposit mortgages to the government’s Lifetime ISA bonus. The tricky part is knowing exactly how much you need, which scheme fits your situation, and the fastest route to get there.

The 5%, 10%, and 20% Deposit Thresholds — What Each Gets You

Mortgage lenders price their deals based on loan-to-value (LTV) — the percentage of the property’s price you need to borrow. The lower your LTV, the less risk to the lender and the better the rate you’ll be offered.

• 5% deposit (95% LTV) — The minimum most lenders accept. Mortgages at this level exist, including via the government’s Mortgage Guarantee Scheme, but rates are significantly higher than at 90% LTV. A 95% mortgage on a £250,000 property can cost £100–150/month more than the equivalent at 90%.
• 10% deposit (90% LTV) — The sweet spot for most first-time buyers. The range of lenders widens considerably, rates improve materially, and the total interest paid over a 5-year fixed term drops by several thousand pounds.
• 20%+ deposit (80% LTV or lower) — The best rates and widest lender choice. If you can reach 20%, the monthly saving on the mortgage rate often outweighs the extra time spent saving — worth modelling for your specific property price.

A simple heuristic: if you’re choosing between taking a 5% deposit now or waiting 18 months to reach 10%, it’s usually worth running the numbers on the rate saving. The extra rent paid while you save often costs less than the higher mortgage rate over a 2–5 year fixed term.

Government Schemes for First-Time Buyers

Lifetime ISA (LISA)

The Lifetime ISA is the most powerful deposit-saving tool available to most first-time buyers under 40. You can contribute up to £4,000 per tax year, and the government adds a 25% bonus — up to £1,000 per year — on top. Over five years of maximum contributions, that’s £5,000 in free government money before any interest or investment growth.

Key rules: open it between ages 18 and 39; the property must cost no more than £450,000; it must be your first home; and you must have held the LISA open for at least 12 months before using it. Withdrawing the money for anything else before age 60 triggers a 25% penalty — which claws back the bonus plus 6.25% of your own contributions.

Shared Ownership

Shared Ownership lets you buy a share of a property — typically 10–75% — and pay rent on the rest. Your deposit is based only on the share you’re buying, which reduces the upfront sum. You can “staircase” upward to owning 100% over time. The trade-off: you pay both a mortgage on your share and rent on the remainder, and the combined monthly cost can approach a full purchase mortgage payment on a smaller property.

First Homes Scheme

First Homes offers new-build properties at a minimum 30% discount to eligible buyers, typically key workers, local first-time buyers, and people with connections to the area. Supply is limited and patchy, but where it’s available it represents significant value.

How Much Can You Borrow?

Before you set your deposit target, you need to know your maximum mortgage — because your deposit plus your mortgage equals the property price you can afford.

Most UK lenders use an income multiple as their primary affordability check:

• 4x–4.5x gross annual salary is the typical limit for a single applicant
• 4x–4.5x combined gross salary for joint applicants
• Some lenders offer up to 5x for higher earners or specific professions (healthcare, law, finance)

All lenders also stress-test affordability at a higher interest rate — typically 2–3% above the current deal rate — to check you could still afford repayments if rates rose. Your credit history, existing debt, and monthly commitments all feed in.

Use our financial planning tools to map your full household income and monthly outgoings, so you have a clear picture of what mortgage payment is genuinely sustainable alongside your other goals — not just the maximum a lender will approve.

Stamp Duty Relief for First-Time Buyers

First-time buyers in England and Northern Ireland benefit from Stamp Duty Land Tax (SDLT) relief:

• 0% on the first £300,000 of the purchase price
• 5% on the portion between £300,001 and £500,000
• Standard rates apply above £500,000, and first-time buyer relief disappears entirely if the property costs more than £500,000

For a £300,000 property: zero stamp duty. For a £400,000 property: 5% on the top £100,000 = £5,000. Wales uses Land Transaction Tax and Scotland uses Land and Buildings Transaction Tax — each has its own first-time buyer rules and thresholds.

On a typical first-time buyer purchase in England, the SDLT saving versus a second-time buyer is £2,500–£10,000 — a meaningful contribution to your moving costs.

How Long Will It Take to Save Your Deposit?

As a rough guide using UK average figures:

• UK average house price: approximately £285,000
• 10% deposit on £285,000: £28,500
• Saving £500/month (plus LISA bonus where eligible): around 4–4.5 years
• Saving £1,000/month: around 2–2.5 years

London buyers face a different picture: average prices of £500,000–£550,000 mean a 10% deposit of £50,000–£55,000, and many buyers either use Shared Ownership, buy in surrounding commuter areas, or save for longer.

Our projection tools let you model your exact situation: input your current savings, monthly contribution, LISA bonus, and target deposit to get a month-by-month timeline showing when you’ll hit your goal — and how different savings rates would change the timeline.

Where to Keep Your Deposit Savings

Where you save your deposit matters almost as much as how much you put away each month.

• Lifetime ISA (for most buyers under 40, property £450k or less) — The 25% government bonus makes the LISA unbeatable. Even a cash LISA paying 3% AER delivers a first-year effective return of around 29% on your contributions once the bonus is counted. Open one as early as possible to start the 12-month clock.
• Cash ISA or easy-access savings account — For savings beyond the £4,000 LISA limit, or if your target property exceeds £450,000, a competitive easy-access account (currently 4–4.5% AER from the best providers) is the right home for a deposit.
• Not stocks and shares (if buying within 2–3 years) — At a short time horizon, market volatility is a real risk. A 20% market fall a year before you buy could delay your purchase by years. Stocks and shares LISAs or ISAs are more appropriate for deposit goals at least 5 years out.

If your situation is complex — near the LISA property cap, considering Shared Ownership, or uncertain about timing — a regulated financial adviser or mortgage broker can help you structure your savings and mortgage approach correctly from the start.