What is a Mortgage Deposit?
A mortgage deposit is the portion of the property price you pay yourself.
The lender covers the rest.
So if you’re buying at £200,000 and putting down £20,000, your deposit is 10% and the lender provides the remaining 90%.
That percentage is what lenders focus on.
Because it directly affects how they assess risk.
How much deposit do I need to buy a house?
In most cases, the minimum is 5%.
That means borrowing 95% of the property value.
But that’s just the entry point.
Where your deposit sits makes a difference to:
- how many lenders are available
- how your case is viewed
- the rates you’re offered
The key thresholds tend to be:
- 5% → limited options, stricter assessment
- 10% → broader lender access
- 15% → noticeably stronger pricing
- 20%+ → more stable position overall
These aren’t exact cut-offs, but moving between them can change your outcome more than small differences in income.
Use our mortgage deposit calculator to work out how long it could take you to save up your target amount.
Why the deposit matters more than people expect
It’s not just about reducing the loan size.
From a lender’s perspective, the deposit is your buffer.
If property values fall, that buffer protects them.
If it’s small, the lender is exposed.
That’s why smaller deposits lead to:
- higher rates
- stricter criteria
- fewer options
And why larger deposits do the opposite.
It’s not a reward. It’s risk control.
What changes as your deposit increases
As your deposit grows, three things tend to improve.
First, pricing.
Rates generally reduce as risk reduces, which lowers your monthly cost.
Second, flexibility.
Lenders are often more comfortable with borderline elements in a case when the deposit is stronger.
Third, resilience.
You’re less exposed to changes in property value and less likely to fall into negative equity.
This is why moving from 5% to 10% or 10% to 15% often matters more than people expect.
Low deposit options (what’s actually available)
If you don’t have a large deposit, there are still options.
95% mortgages are widely available, but assessed more tightly.
100% mortgages do exist in limited forms, but they’re not simple “no deposit” products. They usually rely on additional support, such as:
- a guarantor
- family savings held with the lender
- or another property acting as security
So while you may not provide a deposit directly, the risk is still being covered.
Other costs to factor in
The deposit isn’t the only upfront cost.
You’ll also need to cover:
- stamp duty (where applicable)
- legal fees
- valuation and lender fees
These come from the same pool of savings.
So in practice, your deposit target needs to sit alongside these costs, not instead of them.
Should you wait to increase your deposit?
This depends on what that extra deposit actually changes.
If moving from 5% to 10% or 10% to 15%, the impact can be meaningful.
You may:
- access more lenders
- qualify for better rates
- have more flexibility if your case isn’t perfectly clean
In those situations, waiting can improve your position.
But waiting isn’t always better.
If property prices are rising, or your situation is already strong enough to pass comfortably, delaying may not improve things in a meaningful way.
There’s also a point where increasing your deposit further doesn’t change much.
Going from 25% to 30%, for example, may have very little impact on rates or lender choice.
So the question isn’t just:
should you wait?
It’s:
what does that extra deposit actually unlock?
If it moves you into a stronger bracket, it’s often worth considering.
If it doesn’t, the benefit will be limited.
Final considerations
A deposit isn’t just a hurdle to get over.
It shapes your entire mortgage position.
A smaller deposit can still work, but it narrows your options and increases sensitivity to risk.
A larger deposit improves pricing, flexibility, and stability.
The decision isn’t just “how much can you save”.
It’s how that deposit positions you when a lender assesses your case.
See How Lenders Are Likely to Read Your Case
Most borrowers compare rates before they know whether a lender will actually like their case.
That’s how people waste time with the wrong bank, get weaker offers, or end up with avoidable declines.
The readiness check gives you an early read on how your case is likely to land, where the pressure points are, and whether lender choice needs more care.
- Avoid wrong lenders
- Spot pressure points
- Understand case fit
- Check before applying
See How Lenders Are Likely to Read Your Case
Mortgage Readiness Check
See how lenders will read your case.
Whether the income pattern looks stable enough to rely on, and how much of it they are prepared to include.