If you’re considering buying a property to rent out, you’ll need more than just a vision and a good location—you’ll need the right kind of mortgage. That’s where this buy-to-let mortgage guide comes in.
Buy-to-let mortgages are designed specifically for property investors. Whether you’re planning to rent out a second home or diving into property for long-term income, the process is different from standard residential mortgages—and often, a lot trickier.
In this guide, we’ll cover every crucial detail, from eligibility and income rules to fees and the often-overlooked 3% stamp duty surcharge.
What Is a Buy-to-let Mortgage?
A buy-to-let mortgage is a specialist mortgage designed for individuals purchasing a property to let out, not live in. It differs significantly from a standard residential mortgage and is treated by lenders as a higher-risk product.
Why the higher risk? Because unlike a home you live in, a rental property can sit empty between tenants, which means potential gaps in income.
You’ll need a buy-to-let mortgage even if you’re renting out your current home—unless you get ‘consent to let’ from your lender.
For example: Say you own a flat in Stratford and want to move elsewhere but rent your flat out. You’ll either need that lender’s permission or remortgage with a buy-to-let deal.
How Do Buy-to-let Mortgages Work?
Most buy-to-let mortgages are interest-only. This means you only pay the interest on the loan each month, not the capital. Your monthly payments will be lower, but you’ll still owe the original loan amount at the end of the term.
By contrast, a repayment mortgage pays off both the interest and the loan over time—but this is less common in the rental property market because it reduces monthly profit.
Visit MoneyHelper’s comparison of mortgage types
Key Differences from Residential Mortgages
Buy-to-let mortgages have some standout differences:
- Higher deposit requirements – typically a minimum of 25%
- Higher fees – arrangement fees can exceed 2% of the loan
- Higher interest rates – often 0.5% to 1% more than standard mortgages
- Rental income coverage rules – lenders usually require rental income to be 125–145% of your mortgage payments
Additionally, affordability isn’t just about your income. Lenders stress-test your potential rental income against interest rates as high as 7.5% to check viability.
So if a property costs £250,000, expect to pay a deposit of at least £62,500. If your monthly mortgage payment is £1,000, your rental income needs to be at least £1,250–£1,450 to qualify.
Visit the FCA guide on mortgage affordability
Can I Get a Buy-to-let Mortgage?
You may be eligible for a buy-to-let mortgage if:
- You earn at least £25,000 a year (most lenders set this as a minimum)
- You already own your own home (either with a mortgage or outright)
- You have a good credit score and minimal outstanding debt
- You’re within the lender’s age limits—typically under 75 at the end of the mortgage term
Each lender varies, so if you’re older or have a complex financial background, using a mortgage broker is highly recommended.
Visit Experian’s free credit score check
How Much Can I Borrow?
The key question for most landlords is, how much can I borrow?
Lenders base your maximum loan amount primarily on projected rental income rather than your salary. Some may also look at your broader financial commitments, including debts or existing mortgages.
Your property’s value and expected rent are crucial. For example:
- If you expect to charge £1,500/month in rent
- Your mortgage repayment is £1,000/month
- Your rent-to-mortgage coverage is 150%, which clears most lender requirements
You’ll also need to consider loan-to-value (LTV). This is the percentage of the property value you’re borrowing. Buy-to-let lenders often cap LTV at 75%.
Interest Rates and Arrangement Fees
At present, buy-to-let mortgage rates sit between 5% and 7%, with the best deals typically reserved for those with higher deposits (40%+).
But the catch? Low interest rates often come with hefty arrangement fees, sometimes reaching into the thousands. When comparing mortgages, always consider the full cost over time.
Tip: A slightly higher rate with lower fees might save you more in the long run.
Mojo Mortgages – no-fee whole-of-market broker
Where to Find the Best Buy-to-let Mortgage?
You can apply directly with a lender or go through a mortgage broker, who can help match you with the best deal from 70+ lenders and explain complicated terms.
Some brokers, like Mojo Mortgages, offer no-obligation consultations and don’t charge fees—ideal if you’re just exploring your options.
Don’t Forget the Stamp Duty Surcharge
If this property will be your second home (even if your main one is overseas), you’ll pay a 3% stamp duty surcharge on top of the normal rates.
And that surcharge applies to the entire purchase price—not just the portion above a threshold.
Example: For a £300,000 buy-to-let, the 3% surcharge alone is £9,000. Add that to the standard £5,000 stamp duty, and you’re looking at a total of £14,000 upfront.
| Property Price Band | Regular SDLT | With 3% Surcharge |
| £0 – £125,000 | 0% | 3% |
| £125,000 – £250,000 | 2% | 5% |
| £250,000 – £925,000 | 5% | 8% |
Final Thoughts
Becoming a landlord in the UK can be a smart long-term investment. But understanding the ins and outs of a buy-to-let mortgage is essential before diving in.
From the higher deposit requirements and stricter rules to potential fees and tax implications, this buy-to-let mortgage guide is designed to help you navigate the process confidently and make informed decisions.
And remember: the best deals often go to those who plan ahead, speak to brokers, and know their numbers.
