A Joint Borrower Sole Proprietor mortgage, often shortened to a JBSP mortgage, can be a valuable solution for buyers who need support with affordability while still wanting to own a property in their own name. 

A Joint Borrower Sole Proprietor mortgage allows multiple people to be responsible for the mortgage repayments, while only one person is named as the legal owner of the property. 

Understanding how a JBSP mortgage works, who it is suitable for and the implications involved is essential before proceeding.

Katherine Mumford, Mortgage Broker in Tottenham, North London said:

“A Joint Borrower Sole Proprietor mortgage can be a powerful stepping stone onto the property ladder, but it needs to be set up carefully. At Thomas Oliver, we take the time to understand both the buyer’s goals and the supporting borrower’s position, ensuring the solution works for everyone involved.”

What is a Joint Borrower Sole Proprietor mortgage (JBSP mortgage)?

A Joint Borrower Sole Proprietor mortgage is a mortgage arrangement where two or more people take joint responsibility for the mortgage repayments, but only one borrower is registered as the legal owner of the property at the Land Registry. 

All borrowers’ incomes can be considered by the lender when assessing affordability, even though ownership remains with a single individual. This structure is most commonly used to help buyers who cannot meet affordability requirements on their own.

How does a JBSP mortgage work in practice?

With a JBSP mortgage, all named borrowers are equally responsible for meeting the monthly mortgage repayments, regardless of who owns the property. If repayments are missed, the lender has the right to pursue any of the borrowers for the full amount owed. 

However, only the sole proprietor has ownership rights to the property, including the right to live in it or benefit from any increase in value.

Who are Joint Borrower Sole Proprietor mortgages suitable for?

Joint Borrower Sole Proprietor mortgages are often used by first-time buyers who are being supported by parents or close family members, but they can also be suitable for professionals whose income is expected to rise in the future. 

A JBSP mortgage can help buyers access higher borrowing amounts without needing to add another person to the property deeds, which can be important for tax, legal or personal reasons.

Who can help me obtain a JBSP mortgage?

Not all lenders offer Joint Borrower Sole Proprietor mortgages, and those that do often apply different criteria regarding age limits, income assessment and maximum borrowing. 

A professional mortgage broker, such as Thomas Oliver, can identify which lenders are currently offering JBSP mortgage products and assess which options are most suitable for your individual circumstances, both now and in the future.

What are the benefits of a Joint Borrower Sole Proprietor mortgage?

One of the key advantages of a JBSP mortgage is improved affordability, as multiple incomes can be used to support the application. This can allow buyers to access better properties or purchase sooner than would otherwise be possible. 

Another benefit is that supporting borrowers do not appear on the property title, which can help avoid additional stamp duty or complications with future property ownership.

Are there any disadvantages to a JBSP mortgage?

While a JBSP mortgage can be extremely helpful, there are potential drawbacks to consider. All borrowers are financially liable for the mortgage, which means missed payments can affect everyone’s credit profile. 

Supporting borrowers may also find that their ability to borrow in the future is reduced, as the JBSP mortgage will be taken into account by other lenders.

Who owns the property with a JBSP mortgage?

With a Joint Borrower Sole Proprietor mortgage, the property is legally owned by the sole proprietor only. The additional borrowers do not have ownership rights and are not entitled to proceeds if the property is sold, unless a separate legal agreement is put in place. 

Many buyers choose to take independent legal advice to ensure everyone fully understands their position.

Can a JBSP mortgage be changed in the future?

Yes, many JBSP mortgages are designed to be temporary. As the sole proprietor’s income increases, it may be possible to remortgage into a standard sole borrower mortgage, removing the supporting borrowers from the loan. 

Professional mortgage advice is particularly important here, as lenders’ criteria and affordability assessments can change over time.

Why is professional mortgage advice important for a JBSP mortgage?

A Joint Borrower Sole Proprietor mortgage involves financial, legal and long-term planning considerations that go beyond a standard mortgage. 

Professional advice ensures that the mortgage is structured correctly, that all borrowers understand their responsibilities, and that future options such as remortgaging or buying additional property are not unintentionally restricted.

How can Thomas Oliver help with a Joint Borrower Sole Proprietor mortgage?

Thomas Oliver provides clear, tailored mortgage advice, helping clients understand whether a JBSP mortgage is suitable and which lenders are best aligned to their needs. By offering guidance from initial enquiry through to completion and beyond, Thomas Oliver ensures clients feel informed, supported and confident in their decisions.

Ultimately, a Joint Borrower Sole Proprietor mortgage can offer valuable flexibility, but it is not a one-size-fits-all solution. Taking the time to fully understand how a JBSP mortgage works, the responsibilities involved and how it fits into your wider financial plans is crucial. With the right professional guidance, it can be a well-structured route onto or up the property ladder, providing reassurance for both the buyer and any supporting borrowers.

Speak to Thomas Oliver today

If you are considering a Joint Borrower Sole Proprietor mortgage or would like to explore whether a JBSP mortgage could help you achieve your property goals, speak to Thomas Oliver today. Expert, friendly advice can make all the difference in finding the right mortgage solution for your circumstances.

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YOUR HOME MAY BE REPOSSESSED IF YOU DO NOT KEEP UP REPAYMENTS ON YOUR MORTGAGE.

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HM Revenue and Customs practice and the law relating to taxation are complex and subject to individual circumstances and changes which cannot be foreseen.

Thomas Oliver UK LLP is an appointed representative of The Openwork Partnership, a trading style of Openwork Limited which is authorised and regulated by the Financial Conduct Authority.

Approved by The Openwork Partnership on 29/01/2026.

Sources: HM Land Registry - GOV.UK, First Time Buyer & Family Assisted Mortgages | Family Building Society, Income Booster | Joint Borrower Sole Proprietor mortgages, What is a Joint-Borrower-Sole-Proprietor Mortgage?, What Is a JBSP Mortgage? How Joint Borrower Sole Proprietor Mortgages Work | Mortgage Bridge, Compare Best Joint Borrower Sole Proprietor Mortgages (JBSP) | money.co.uk