If you are considering purchasing a property with financial assistance from someone else, a Joint Borrower, Sole Proprietor (JBSP) mortgage might be a suitable option. This type of mortgage allows multiple individuals to contribute to the mortgage repayments without all of them being legal owners of the property.
A JBSP mortgage can improve your chances of securing the home you want, as the combined income of all borrowers is considered during the application process. This can increase the amount you are eligible to borrow.
In this guide, we’ll explain the steps to take when applying for a JBSP mortgage, how borrowing capacity is assessed, and what the potential tax implications are for those involved.
What is a joint borrower, sole proprietor (JBSP) mortgage?
A Joint Borrower, Sole Proprietor (JBSP) mortgage enables a property purchase with multiple applicants—typically up to four—while only one individual is registered as the legal owner and resident. The additional borrowers are not named on the title deeds and do not hold any legal claim to the property or benefit from any increase in its value.
This type of borrowing arrangement is becoming increasingly popular, particularly among families wishing to support a home purchase. It offers a way for the main applicant to access financial support from others without sharing ownership. JBSP mortgages are especially beneficial for first-time buyers aiming to step onto the property ladder, or for older applicants such as pensioners who may have reduced or no income from employment.
All applicants share equal responsibility for repaying the mortgage, which reduces the lender’s risk. Leveraging the combined financial strength of multiple borrowers can improve your borrowing capacity, enhance access to competitive mortgage terms, and potentially secure lower interest rates.
Eligibility criteria
When applying for a Joint Borrower, Sole Proprietor (JBSP) mortgage, lenders will evaluate the financial circumstances of both the primary applicant and any additional borrowers listed on the application.
While specific criteria may differ between lenders, the key factors typically assessed include:
- Deposit: The size of your deposit directly influences the loan-to-value (LTV) ratio. A larger deposit, which results in a lower LTV, is generally viewed more favourably as it reduces the lender’s exposure to risk—an important consideration for JBSP mortgages.
- Credit history: Lenders will conduct a detailed review of the credit profiles of all applicants. Ideally, each borrower should have a strong credit history; however, there are still viable options if one or more parties have adverse credit, though this might affect the choice of lenders and terms available.
- Income and affordability: All applicants’ incomes, financial commitments, and outgoings will be scrutinised to assess affordability. Lenders want to be confident that the collective income is sufficient to cover the monthly mortgage repayments comfortably.
- Age restrictions: Most lenders stipulate that the mortgage must be repaid by the time the oldest borrower turns 80. This could impact the loan term, particularly if older family members, such as parents or grandparents, are included in the application. A shorter mortgage term may result in higher monthly repayments.
Understanding these factors will help you prepare effectively for a JBSP mortgage application and increase your chances of securing favourable terms.
How much can you borrow?
This is where having additional borrowers can be especially advantageous—particularly if you're applying on the basis of a single income.
Ordinarily, lenders may allow you to borrow around 4.5 times your annual salary. However, with a Joint Borrower, Sole Proprietor (JBSP) mortgage, all applicants’ incomes can be factored into the lender’s affordability calculations, significantly increasing your potential borrowing limit.
For instance, if your income is £30,000 per year, you might only qualify for a mortgage of approximately £135,000. But by including two additional borrowers—each also earning £30,000—your total annual income used for the assessment could rise to £90,000, potentially raising your borrowing capacity to around £405,000.
This collective approach can make purchasing a higher-value property far more achievable.
How to get a JBSP mortgage
A number of lenders provide Joint Borrower, Sole Proprietor (JBSP) mortgages, but navigating the process can be complicated—and potentially costly—without the right advice.
It’s essential to ensure you’re working with a lender that suits your individual circumstances. This may mean identifying those who can offer the highest possible loan amount, the most competitive interest rates, or those who are more flexible when dealing with complex applications involving supporting borrowers.
For situations that include unique financial arrangements, adverse credit, or older applicants, a specialist mortgage broker can be invaluable. They can guide you through the available options, liaise with suitable lenders, and help you avoid common pitfalls, ensuring the most suitable and cost-effective solution is found for your needs.
Lenders offering this type of mortgage
A Joint Borrower, Sole Proprietor (JBSP) mortgage can be arranged through a broad range of lenders. However, eligibility requirements and interest rates can differ significantly depending on the provider.
Some high street banks, including Barclays and Metro Bank, may impose stricter criteria or offer less competitive terms for JBSP arrangements. In contrast, building societies and specialist lenders such as Skipton Building Society and Bath Building Society often provide more flexible options and potentially more attractive rates.
Given the wide variation in lending policies, it is highly advisable to consult with a mortgage broker. A broker can assess your specific circumstances and help identify the lenders offering the most suitable and cost-effective deals, ensuring you secure the most favourable outcome for your situation.
Alternative options
Depending on your financial situation and goals, there are several alternative mortgage and financing options worth considering alongside a Joint Borrower, Sole Proprietor (JBSP) mortgage:
- Guarantor mortgages: These allow a parent or close relative to support your mortgage by acting as a guarantor. They commit to covering the repayments if you’re unable to, offering reassurance to the lender and potentially improving your eligibility.
- Joint mortgages: In this arrangement, all applicants are named on both the mortgage and the property’s title deeds. This can be structured either as joint tenants—where ownership is shared equally—or as tenants in common, where each person holds a defined share in the property.
- Family springboard mortgages (also called ‘deposit boost’): These are designed to help first-time buyers purchase a property without a deposit. Instead, a family member provides security, typically by depositing savings into a linked account or using their own home as collateral. These funds act as a temporary guarantee until a certain portion of the mortgage is repaid.
Each of these options has its own benefits and considerations. It’s advisable to discuss your full financial picture with a mortgage adviser to identify which route offers the most suitable and affordable solution.
Tax implications to consider with JBSP mortgages
Since the sole proprietor—i.e., the individual who will reside in the property—is the legal owner, they alone are responsible for any tax liabilities, including Stamp Duty Land Tax (SDLT) at purchase and potential Capital Gains Tax (CGT) upon sale.
One key advantage of this structure is that the tax position of the other joint borrowers does not affect the transaction. For instance, if the sole proprietor is a first-time buyer, they may still qualify for SDLT relief, even if the supporting borrowers already own property. Similarly, only the sole proprietor would be considered for any future CGT liabilities, meaning joint borrowers are excluded from these calculations.
Nonetheless, tax situations can be complex and vary widely depending on individual circumstances. It’s strongly recommended to seek advice from a qualified tax adviser to ensure the most tax-efficient outcome and full compliance with current regulations.
Advantages and disadvantages
The table below shows the pros and cons of a joint borrower, sole proprietor mortgage at a glance so you can get a clearer idea of whether it’s right for you.
| Advantages | Disadvantages |
| It can make it easier to qualify for a mortgage | All applicants are jointly liable for the monthly repayments |
| The ability to borrow more money | It can’t be used with some government schemes |
| Potentially access lower rates and deals | They can be a complex arrangement to enter and exit |
| Help people get on the property ladder faster | You might face an age limit with older borrowers |
| Lower risk for lenders means more favourable mortgage terms | Only certain lenders will offer top deals |
Frequently Asked Questions
JBSP mortgages are mostly designed for residential purchases. Some specialist lenders might be open to discussing buy-to-let mortgages under the right circumstances, or explore whether a loan can be tailored to your needs.