Joint Borrower Sole Proprietor
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Joint Borrower Sole Proprietor (Part 1)
Joe Capon explains how a Joint Borrower Sole Proprietor (JBSP) mortgage works.
Podcast approved by The Openwork Partnership on 30/12/2025.
What is a Joint Borrower Sole Proprietor mortgage?
A JBSP mortgage is where you buy a property and a parent or family member goes on the mortgage with you. It’s normally to boost affordability. Importantly, the supporting family member doesn’t go on the ownership of the property.
The mortgage is processed just like a traditional product, and normal criteria are taken into account – such as age, income and expenditure.
The only extra step is for the family member to take independent legal advice, to make sure they understand that they are liable for the mortgage, but they have no responsibility over the property – because they’re not on the ownership.
What responsibilities do the joint borrower and sole proprietor have in a JBSP mortgage?
The joint borrower on the mortgage needs to understand that they are fully responsible for the mortgage repayments – and that any missing payments can affect their credit file.
Also, because they’re not on the ownership of the property, they have no legal ties over it. The person they’re helping is the sole owner – or proprietor – of that property.
That’s always checked as part of the process. The lender needs proof that the joint borrower has received independent legal advice.
Who is eligible for a JBSP mortgage? Can I get a JBSP mortgage as a first-time buyer?
Anyone looking to own a property is eligible for a JBSP mortgage, but it’s most commonly used by first-time buyers to boost affordability. It can also help people move home or even remortgage a current property, however. Remortgages are rare, but we have done it.
It’s mainly used where first-time buyers are falling short on affordability. They need that extra borrowing and they know the repayments are within their budget. A JBSP can get around traditional mortgage criteria on affordability – by adding someone on, their income is also taken into account. It’s a good way to get on the property ladder to buy a first home.
What criteria do you need to meet for a JBSP mortgage?
The criteria for a JBSP mortgage are very similar to a traditional mortgage. A lender takes into account your income, your age, credit score, expenditure and credit commitments. The size of your deposit is also important.
The lender uses that information to confirm how much they can lend. Normally with a JBSP mortgage, that will be more than the child or family member could borrow on their own.
It allows them to buy the property they want, so it’s mainly a way to boost affordability.
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Do JBSP mortgages require a larger deposit compared to standard mortgages?
No, not necessarily. There are options with a deposit as low as 5%. Just like traditional mortgages, though, the size of your deposit will influence how much you can borrow against the price of a property you want to buy.
Everyone’s in a different situation, so it’s always decided case by case. Seek advice from a mortgage adviser who’s experienced in JBSP mortgages, and we’ll run through how much you can borrow and what that’s likely to cost you.
Do you pay stamp duty on a JBSP mortgage?
Potentially, yes, but the main reason to use a JBSP mortgage – apart from needing to borrow more money – is to avoid stamp duty.
If a parent or family member took a traditional joint mortgage with the main borrower and that family member owns their own home, additional stamp duty would normally be due. To the family member, it would be an additional property.
On a JBSP mortgage, not only can you boost borrowing, but the family member isn’t on the property deeds. If the main applicant is a first-time buyer they can still access first-time buyer stamp duty rates – which could either be zero or very minimal, depending on the purchase price.
It’s so important to get the right advice – otherwise a parent who already owns a property could face a large stamp duty liability.
Can you have a sole mortgage on a joint property?
A few lenders used to allow this, but in recent years it has stopped. Any person on the ownership of a property will also need to be on the mortgage.
What’s the difference between a joint mortgage and a JBSP mortgage?
On a traditional joint mortgage, both borrowers are named on the mortgage and also on the ownership. On a JBSP mortgage, only one of the borrowers is on the ownership. That’s the main difference.
What’s the difference between a guarantor mortgage and a JBSP mortgage?
They are very similar – in some ways they are the same. But with some guarantor mortgages, the borrowing isn’t necessarily a factor. Instead it’s to overcome challenges with saving up a deposit.
A parent or family member could put forward their savings in place of a deposit – normally about 10% of the purchase price. These are held in a designated savings account with the lender. They still gain interest on the savings, but they are held in that account for around five years. As long as the mortgage holder keeps up their payments, they can withdraw the savings later.
With a JBSP mortgage there does need to be some form of deposit – normally at least 5% of the purchase price. A parent and child go on the mortgage, but the child will be the sole owner of that property.
What are the pros and cons of JBSP mortgages?
The main benefit of a JBSP mortgage is being able to borrow more money. It can get you onto the property ladder or help you move to a bigger home, by increasing the income on the mortgage application.
At the same time, you potentially avoid additional stamp duty, especially if the family member going on the mortgage owns their own home.
The downside of a JBSP mortgage is that the family member is liable for the mortgage payments if the main applicant can’t make them. The mortgage will also be on their credit file. They need to receive independent legal advice on that, as they are liable for the mortgage, but will have no say over the property as they’re not owners.
Another disadvantage is that if the family member is older, their age could reduce the length of the mortgage term. That will push up mortgage repayments and potentially make them unaffordable for the person living in the property.
Is there anything else we need to know about Joint Borrower Sole Proprietor mortgages?
We’ve covered quite a lot of information, but if there’s any other questions people have, please contact us. We’ll happily answer those for you.
Key Takeaways:
- A Joint Borrower Sole Proprietor (JBSP) mortgage allows a parent or family member (the joint borrower) to go on the mortgage with you to boost affordability, but they do not go on the ownership of the property.
- The joint borrower is fully responsible for the mortgage repayments, and missing payments will affect their credit file, even though they have no legal tie or say over the property.
- It is most commonly used by first-time buyers who are struggling with affordability, as adding the family member’s income is taken into account by the lender.
- JBSP mortgages do not necessarily require a larger deposit compared to standard mortgages, with options available for deposits as low as 5%.
- A key benefit is the potential to avoid additional stamp duty, as the supporting family member is not on the property deeds. If the main applicant is a first-time buyer, they can still access first-time buyer stamp duty rates.
YOUR PROPERTY MAY BE REPOSSESSED IF YOU DO NOT KEEP UP REPAYMENTS ON YOUR MORTGAGE.
Approved by The Openwork Partnership on 30/12/2025.