Million-Pound Buy-to-Let Mortgages: A Landlord's Guide to Large-Loan Lending

Million pound mortgage: what it means

A “million pound mortgage” is simply a mortgage for £1,000,000 or more. At that level, the process is broadly similar to other mortgages, but underwriting is typically more detailed and lenders often expect stronger evidence around affordability, deposit, property value and overall risk.

For many borrowers, the key difference is not that the rules are completely different—it’s that the information lenders request tends to be more specific, and the product options may be narrower depending on the exact circumstances.

How lenders assess a million pound mortgage

While each lender has its own approach, most will look at the same core areas:

• Deposit and equity: Larger borrowing usually requires a more substantial deposit to reduce lender risk.
• Affordability: For residential borrowing, lenders assess whether the borrower can make the payments reliably.
• Income evidence: Lenders typically want clear documentation and a consistent employment/earnings history.
• Credit history: Adverse credit doesn’t automatically rule you out, but it can reduce options and may require additional explanation.
• Property valuation: The property must be valued at a level that supports the loan amount.
• Terms and structure: The chosen mortgage type (for example, repayment vs interest-only) can affect what lenders will accept.

Interest-only vs repayment at £1m+

One reason million pound borrowers often explore flexibility is that the mortgage structure can be tailored to how income is received.

Interest-only

An interest-only mortgage means you pay the interest each month, while the capital is due later (for example, via savings, investments, or a sale/remortgage plan). Lenders generally scrutinise the repayment strategy more closely at higher loan sizes.

Repayment

A repayment mortgage pays both interest and capital over the agreed term. This can be simpler to manage, but monthly payments may be higher than interest-only.

In practice, the “best” option depends on cashflow, risk tolerance, and how confident you are about your plan for clearing the capital.

Fixed-rate periods: two-year vs five-year (and beyond)

At million pound levels, borrowers commonly consider longer fixed terms to manage uncertainty.

Fixed rates are influenced by market expectations and lender funding costs, so the relative pricing between shorter and longer fixes can change over time. Rather than focusing only on which term is “cheaper”, it’s often more useful to compare:

• Total cost over the fixed period
• Early repayment charges (if you might refinance or sell)
• How long you want payment certainty
• Whether the lender’s product allows flexibility (for example, overpayments, where available)

Fees and valuations on higher-value lending

Million pound mortgages can involve additional costs compared with smaller loans, although the exact fee structure varies by lender and product.

Common considerations include:

• Arrangement fees: Many lenders charge a fee on higher loan amounts.
• Valuation approach: Some lenders may include a basic valuation on certain applications, while others may charge for valuations—particularly on higher-value properties.
• Legal and completion costs: These are part of any mortgage transaction, and the overall timeline can be influenced by how complex the case is.
• Bespoke products: On larger amounts, it’s sometimes possible for lenders to consider more tailored solutions, though this is not guaranteed.

Bad credit and million pound borrowing

Bad credit can restrict options, but it doesn’t always mean the answer is automatically “no”. The deciding factor is usually what the adverse history was, how recent it is, and how the overall application is presented.

Lenders may ask for context such as:

• Whether missed payments were tied to a specific event
• How long ago the issues occurred
• Whether there has been a sustained period of improved credit behaviour

A detailed application and clear supporting evidence can be important at this level, because lenders are balancing risk carefully.

Income types: bonuses, commission and irregular earnings

Million pound mortgages often involve income that isn’t purely basic salary. Lenders may accept bonus and commission income, but they typically want evidence and may apply a cautious approach.

Common underwriting themes include:

• Using a track record (for example, looking at recent history)
• Not counting all of the variable income (lenders may take only a proportion)
• Assessing stability (whether the income is consistent and likely to continue)

If your income comes from a sector where earnings vary, the way it’s evidenced can significantly affect what lenders will consider.

Foreign currency income

Some lenders may consider income paid in foreign currency, but acceptance is not universal.

Where foreign income is considered, lenders often look for:

• Major currencies (for example, currencies that are generally less volatile)
• Evidence of the income and how it is received and taxed
• Stability and whether the lender can model affordability appropriately

If the currency is highly volatile, lenders may be less likely to accept it.

Remortgaging a million pound mortgage

Remortgaging at £1m+ is usually similar in structure to other remortgages: an application is submitted, the lender reviews the case, and if approved, a formal offer is issued.

The process can still involve:

• Valuation and underwriting
• Legal work to move the mortgage to the new lender
• Product selection based on the borrower’s goals (for example, term length, fixed period, and repayment strategy)

At higher values, additional internal checks may be required, which can affect timelines.

Million pound buy-to-let mortgages: what’s different

A million pound buy-to-let mortgage is still a mortgage for £1,000,000+, but the underwriting is often more focused on the rental proposition than personal income.

How lenders assess buy-to-let

Buy-to-let lending generally considers:

• Expected rental income based on the property’s value and the tenancy arrangement
• Affordability from the rental cashflow (how comfortably the rent can cover the mortgage costs)
• Property risk factors such as location, type, and valuation

In some cases, lenders may also take a wider view of the borrower’s overall financial position, particularly where the rental income alone doesn’t provide the level of cover the lender requires.

Interest-only buy-to-let at high loan sizes

Interest-only structures can be considered in buy-to-let, but lenders may scrutinise the overall risk more closely. Evidence of the plan for the capital repayment (or how the loan will be cleared later) can be particularly important.

Deposits and property value matter more

At higher loan amounts, lenders often expect stronger equity positions. The deposit and the property’s valuation can be central to whether a lender is comfortable with the overall risk.

Working with a specialist approach

At £1m+ and especially for complex buy-to-let cases, the application is often more document-heavy and requires careful presentation.

A specialist approach can help ensure the application aligns with how lenders typically assess higher-value mortgages—particularly where there are variables such as:

• interest-only vs repayment preferences
• irregular income (bonuses/commission)
• adverse credit history
• foreign currency income
• remortgage timelines
• buy-to-let rental cover and property valuation

Important notes

• Your property may be repossessed if you do not keep up with your mortgage repayments.
• The Financial Conduct Authority does not regulate most buy-to-let mortgages.