You’ve found the rental property you want. The big question now: how much mortgage deposit do you need? For most buy-to-let mortgages, it’s 25%. A handful of specialist lenders offer deals at 20%, but these typically come with higher rates and stricter checks. In reality, 25% is the figure you’ll see again and again.
How Much Deposit for a Buy to Let Mortgage?
Most mortgage lenders stick with a 25% deposit as the minimum starting point. You might find the odd 20% deal, but they usually come with higher rates, bigger fees, and stricter checks.
To put it simply:
- 20% deposit → Limited to specialist lenders, higher rates, and usually higher product fees.
- 25% deposit → Standard across the market, with the broadest choice of lenders.
- 40–50%+ deposit → Unlocks the best deals and the lowest buy-to-let rates.
If you’re starting out, check our mortgage broker Buy to Let Mortgage guide for the full picture on how deposits, rental income, and mortgage lender checks all work together.
What Is the Lowest Deposit for a Buy to Let Mortgage?
The lowest realistic buy to let deposit is 20%. A few specialist lenders, like Accord, Molo Finance, or Vida Homeloans, sometimes offer these deals, but they’re rare and short-lived.
It’s worth knowing:
- 20% deals cost more in interest and fees.
- 25% is the true baseline for most lenders.
- 15% buy to let mortgages have existed (e.g. Vida Homeloans), but they’re rare, come with high rates, and aren’t widely available.
Lowest Deposit Buy to Let Mortgage – Is It Worth It?
On the surface, a smaller or minimum deposit looks tempting. Less money tied up. Quicker entry into property investment. The reality is: you’ll often face a higher mortgage interest rate, higher fees, and fewer choices. Sometimes, less upfront ends up costing you more in the long run.
Case Study: Why a 25% Deposit on Your BTL Can Save You £20,000
Our customer Sarah bought a £400,000 buy to let with a 25% deposit (£100,000). That left her a £300,000 mortgage at an average rate of ~2.7%. On an interest only deal, her monthly payments came in at roughly £685.
Our other customer James wanted to keep more cash in his pocket, so he went in with just a 20% deposit (£80,000). He saved £20,000 upfront, but his mortgage was larger at £320,000. The best rate he could find was closer to 3.8%, which meant paying about £1,020 per month in interest.
The outcome? James saved £20,000 on his deposit, but over five years he paid almost £20,000 extra in interest compared with Sarah. What he held back upfront, he lost in higher monthly mortgage costs.
How Deposit Size Affects Your Interest Rate
Here’s how deposit size usually impacts rates, lender choice, and the mortgage amount based on a £400,000 buy-to-let purchase property:
| Deposit Size | Deposit Amount | Mortgage Amount | Avg. Interest Rate* | Lender Access | Notes / Examples |
|---|---|---|---|---|---|
| 20% (minimum) | £80,000 | £320,000 | ~3.79% | Very few lenders | Higher fees, higher risk loans, mostly specialist lenders (e.g. Molo Finance, Accord) |
| 25% (standard) | £100,000 | £300,000 | ~2.71% | Most lenders | Widest choice of buy to let mortgages, mainstream and specialist lenders |
| 40% (strong) | £160,000 | £240,000 | ~2.25% | Many lenders | Unlocks stronger rates, often reserved for experienced landlords |
| 50% (very strong) | £200,000 | £200,000 | ~2.18% | Broadest choice | Best buy to let mortgage deals, lowest rates, accepted by most lenders including high street banks |
Rates shown are examples based on live buy to let mortgage deals available in August 2025. Actual rates change frequently and depend on your circumstances and the lender’s criteria.
Want to check today’s lowest buy to let deals? See our best mortgage rates page.
What Lenders Require for Buy to Let
Most lenders expect you to meet a few key requirements before they’ll offer a buy to let mortgage. In most cases, you’ll need:
- Around 25% deposit upfront – that’s the standard deposit amount lenders require.
- Strong rental income – annual rental income must comfortably cover the loan amount, usually at 125–145% of the mortgage payments.
- A reasonable credit score – a poor credit score can mean needing a larger deposit or being restricted to fewer lenders.
- Acceptable property type – standard houses and flats are fine, but a house in multiple occupation or a quirky property often means specialist lenders and a substantial deposit.
Lenders view buy to let as higher risk, so they look for these checks to reduce the chance of problems later. Meeting them upfront makes it easier to access the better mortgage deals.
Other Factors That Affect Your Buy to Let Deposit
The size of your deposit isn’t the only thing lenders look at. A few other factors can make a big difference:
Deposit sources
Most lenders are OK with deposits coming from personal savings, inheritance, the sale of another property, or capital raised through remortgaging. Gifted deposits are sometimes accepted, but many lenders are stricter when it comes to buy to let, so your options may narrow.
Your credit score
While rental income is key, your credit profile still plays a role. A strong score can open doors to lower deposit options. A weaker score usually means lenders will ask for more upfront, sometimes 35–40%, to reduce their risk.
Other costs
The deposit isn’t the only cash you’ll need. Stamp duty on second homes, legal fees, valuations, and letting agent costs all add up. For example, stamp duty on a £250,000 rental property would be at least £7,500. Planning for these extras means you won’t be stretched too thin after paying the deposit.
Interest Only vs Repayment Buy to Let Mortgages
Most landlords choose interest-only buy-to-let mortgages. Why? It keeps monthly mortgage costs down and helps the rental income meet the stress test — especially if you’re putting in a smaller deposit.
Repayment mortgages reduce the loan balance over time. But here’s the flip side: the higher monthly mortgage repayments often mean you’ll need a bigger deposit to qualify. For landlords starting out with the lowest deposit, interest-only is usually the path lenders are willing to back.
Key Takeaways on the Lowest Deposit Buy to Let Mortgage
- Most lenders want a 25% deposit.
- 20% is possible, but only with specialist lenders and usually higher rates.
- A larger deposit unlocks better deals, cheaper rates, and more lender choice.
- Don’t forget extra costs like legal fees, stamp duty, and agent fees.
Ready to see if you qualify for a low deposit buy to let mortgage? Our brokers compare deals across specialist and mainstream lenders — get in touch today for free advice.
FAQs
Do all lenders require a 25% deposit for buy to let?
Most do. A few specialist lenders may accept 20%, but the choice is limited and the costs are higher.
Can I get a buy to let mortgage with 15% deposit?
Very unlikely. Almost all lenders set 20% as the absolute minimum.
Does my credit score affect the deposit size?
Yes. A poor credit score usually means lenders will want a larger deposit.
Do buy to let mortgages have higher interest rates?
Yes, especially compared with residential mortgages or when using a lower deposit.
Can first-time buyers get a buy to let mortgage?
It’s possible, but most lenders prefer you to own a residential property already and have a more substantial deposit in place.
What deposit sources do lenders accept for buy to let?
Most lenders accept:
Personal savings
Inheritance
Proceeds from selling another property
Capital raised through remortgaging
Gifted deposits are sometimes allowed, but fewer lenders are comfortable with this on buy-to-let.
Final Thoughts
Everyone wants the lowest deposit buy-to-let mortgage. Who wouldn’t? But the reality is low deposit options usually cost more over time. Save longer, put in more, and you’ll almost always end up with stronger mortgage options, lower rates of interest, and easier monthly costs.
If you’re not sure where you stand, talk to a mortgage broker who lives and breathes buy to let. They’ll know which lenders accept smaller deposits, what lenders require in your situation, and whether that 20% deal is worth chasing — or if waiting a few more months could save you thousands.
If you’d like us to run the numbers for your situation, get in touch for free advice today.
