Let to buy affordability: how both mortgages may be assessed is best understood by separating the general principle from the way an individual lender or insurer will assess a real application. Let to buy normally involves keeping the current home as a rental property while arranging a residential mortgage for a new home. The two mortgage applications need to work together. This guide explains the main factors, evidence and limitations so you can understand residential affordability and rental coverage together. It provides general information rather than a personal recommendation.
What this means in practice
Let to buy normally involves keeping the current home as a rental property while arranging a residential mortgage for a new home. The two mortgage applications need to work together.
The most useful starting point is to identify the objective, gather reliable information and understand which parts of the decision are within your control. The final outcome depends on the lender or provider’s current criteria and, where advice is being given, a review of your individual circumstances.
Before comparing products, write down the outcome you need, the timescale, the evidence you already have and any change in circumstances that may affect the application.
What affects the amount
There is no single figure that applies to everyone. The result depends on the evidence available, the provider’s criteria, existing commitments and the precise structure selected.
- Expected rent on the existing property.
- Equity and deposit for the new home.
- Residential affordability.
- Both properties' mortgage costs.
- Timing and lender requirements.
A fictional household could have the same income as another household but receive a different outcome because their regular commitments, deposit, employment history, property or policy choices differ. The example illustrates why a headline multiple or calculator result is not a recommendation.
What may be assessed
An adviser, lender or provider may need to understand a combination of financial, personal and product-specific information. The areas below are a preparation guide rather than a complete or universal checklist.
- Expected rent on the existing property.
- Equity and deposit for the new home.
- Residential affordability.
- Both properties' mortgage costs.
- Timing and lender requirements.
Evidence and preparation
Providing accurate information at the outset can make the process clearer. Do not alter the way income is drawn, cancel existing cover, commit to a property or make another significant financial decision solely to fit a general guide. Changes should be considered in the context of tax, legal, employment and financial consequences.
- Rental valuation.
- Current mortgage statement.
- Purchase details for the new home.
- Income and expenditure evidence.
- Tenancy and landlord information where requested.
Costs, risks and limitations
A balanced decision considers what the arrangement may achieve and what could go wrong. Important limitations should be considered before relying on a headline rate, benefit, borrowing figure or eligibility statement.
- There may be periods with two mortgage commitments.
- Rental income can stop or fall.
- Capital raising increases secured borrowing.
- Tax and landlord obligations require separate professional consideration.
Criteria, policy definitions, product availability and costs can change. General online information cannot confirm that an application will be accepted or that a future claim will be paid.
How to prepare for an adviser conversation
- Write down the objective and the date by which it needs to be achieved.
- Collect the most recent and complete financial or policy documents.
- List existing borrowing, regular commitments and relevant workplace benefits.
- Identify any expected changes to income, employment, health, property use or household circumstances.
- Prepare questions about total cost, exclusions, flexibility and what happens if circumstances change.
An adviser can use that information to explain which options are available and which criteria may apply. You can read more in the Let to Buy Mortgages guides or learn about let to buy mortgages advice.
Continue your research
For the wider context, start with Let to buy mortgages: how the two-mortgage process works.
