How to save for a house deposit: a realistic UK guide

Photo by Modunite Ltd on Unsplash

If you’ve ever opened a savings app, looked at house prices in your area, and then quietly closed the app again, you’re not alone. Saving for a deposit in the UK can feel like trying to hit a moving target — the more you save, the more prices seem to creep up, and the goalposts never stay still.

But here’s the thing most people get wrong: you almost certainly need less than you think, and there are specific tools designed to make this faster. This isn’t about cutting out coffee or moving back in with your parents for five years (though both might help). It’s about understanding the actual numbers — how much deposit you realistically need, where to put your savings so they work harder, and how long it genuinely takes most people.

This guide walks through the real maths, the accounts worth knowing about, and the mistakes that quietly slow people down.

How much deposit do you actually need?

The “20% deposit” figure gets thrown around a lot, but it’s not a rule — it’s just one option. Most lenders will accept a 10% deposit, and some mortgages are available with just 5% down, particularly for first-time buyers.

Here’s why the deposit size matters beyond just “how much you need to save”: it affects your loan-to-value ratio (LTV) — the percentage of the property’s value you’re borrowing. A smaller deposit means a higher LTV, which usually means a higher interest rate, because the lender is taking on more risk. So a bigger deposit isn’t just about getting on the ladder faster — it can also mean cheaper monthly repayments for years afterwards.

On a £250,000 property, here’s what different deposit sizes actually look like in cash terms:

The jump from 5% to 10% matters more than people expect, because mortgage rates tend to drop in bands. Going from a 10% deposit to a 15% one often makes a smaller difference than going from 5% to 10%. If you’re close to a threshold, it’s worth checking whether a bit more saving pushes you into a cheaper rate bracket.

Where to actually keep your deposit savings

This is the part people overthink or underthink in equal measure. You don’t need anything complicated, but you do need to pick the right type of account, because the wrong one can cost you hundreds of pounds in missed growth or tax.

Your main options:

Easy-access savings account — flexible, no penalties, but typically the lowest interest.

Cash ISA (Individual Savings Account) — your interest grows tax-free, which matters more the bigger your pot gets and the higher interest rates are.

Lifetime ISA (LISA) — designed specifically for first-time buyers (or retirement, but that’s a separate use case). More on this below, because it’s the single most useful account most first-time buyers haven’t heard enough about.

Premium Bonds — not technically savings interest, more like a monthly prize draw. Fine for some of your money, but not a reliable core strategy for a deposit timeline.

The Lifetime ISA: the part most people miss

The Lifetime ISA is genuinely one of the better deals available to first-time buyers, and it’s underused simply because it has rules people find off-putting.

Here’s how it works: you can pay in up to £4,000 a year, and the government adds a 25% bonus on top — so if you save the full £4,000, you get an extra £1,000 added, free. That’s the headline. You can open one if you’re aged 18–39, and keep paying in until you’re 50.

The catches, and they matter:

• The property you buy must cost £450,000 or less.
• You need to have held the account for at least 12 months before using it to buy a home.
• If you withdraw the money for anything other than a first home or retirement, you lose the government bonus and pay a penalty on top — effectively taking back more than just the bonus. Treat this money as locked away for its intended purpose.

For a couple buying together, both people can have their own LISA, meaning potentially £2,000 combined in free government bonus per year between you. Full details and eligibility are on gov.uk’s Lifetime ISA page.

The misconception: “I need to save the whole deposit before I think about anything else”

A lot of people treat deposit-saving as a single number they’re racing towards, with no plan for what happens next. That’s a mistake, because the deposit isn’t the only cash you’ll need.

You’ll also need money for:

• Solicitor/conveyancing fees — typically £1,000–£1,500+
• Survey costs — from around £300 to £1,000+ depending on the type
• Stamp Duty Land Tax (if applicable — first-time buyers get relief up to a certain price, but it’s not unlimited)
• Removal costs, furniture, and the inevitable “the boiler needs fixing” moment

Saving exactly your deposit target and nothing more often means a stressful scramble in the final weeks before completion. A sensible rule of thumb many buyers use: budget an extra 1–2% of the property price on top of your deposit for fees and immediate costs.

How much should you actually be saving each month?

This depends entirely on your target and timeline, but seeing it broken down tends to make it feel more achievable than an abstract “save more” target.

(These figures ignore interest or the LISA bonus for simplicity — both would reduce the monthly amount needed, sometimes significantly, especially with the LISA’s 25% top-up.)

If the number for your timeline feels impossible, that’s useful information, not a failure. It tells you to either extend the timeline, look at a lower deposit percentage, consider a cheaper target area, or look at whether family support or a shared ownership scheme changes the maths. None of these are admissions of defeat — they’re just different routes up the same hill.

What if you’re starting from zero?

Plenty of people reading this have no deposit savings at all yet, and that’s completely normal — not a sign you’re behind some invisible schedule. Start here:

1. Work out your actual monthly surplus. Not a guess — look at three months of bank statements and see what’s genuinely left after essentials.
2. Open a Lifetime ISA if you’re eligible, even with a small initial deposit, so the 12-month clock starts running.
3. Automate a transfer the day you get paid, before you see the money sitting in your current account.
4. Check if you’re eligible for other schemes — such as shared ownership, which lets you buy a percentage of a property and pay rent on the rest, lowering the deposit you need upfront. MoneyHelper’s home buying guidance is a solid, impartial place to compare options.

Mistakes that quietly slow people down

Chasing the “best” interest rate instead of the right account type. A slightly higher rate on an account without the LISA bonus still loses to a LISA, because 25% free money beats almost any interest rate available.

Treating the deposit fund like an emergency fund. If your deposit savings are also your safety net for a broken boiler or lost job, you’ll end up dipping into it and restarting your progress. Keep them separate where possible.

Waiting for the “right time” to start. House prices and mortgage rates will keep moving regardless of what you do. The version of this plan that works is the one you start now, even with a small amount.

The bottom line

• Work out your realistic deposit target based on 5%, 10%, or 15% of a property price in your actual target area — not an assumed 20%.
• If you’re eligible, open a Lifetime ISA now, even with a small amount, to start the 12-month countdown and begin earning the 25% government bonus.
• Budget an extra 1–2% of the property price on top of your deposit for fees, surveys, and moving costs — don’t let this ambush you at completion.
• Automate your savings transfer on payday so the house deposit comes out of your routine, not your willpower.
• If the monthly number for your target feels unrealistic, tre

Next read: none