If a parent is willing to help but a gifted deposit is not the answer, book a 15 minute call and I will check which lenders would take the case. Call 01425 203055 or WhatsApp 07731 675537.
HTG Mortgages
What Is a Joint Borrower Sole Proprietor Mortgage?
Last Updated: September 2026
Featured in The Telegraph • Daily Mail • The Times • Sky News
A joint borrower sole proprietor mortgage (JBSP) is one where two or more people are named on the mortgage and responsible for paying it, but only one of them owns the property. The usual case is a parent joining a child’s mortgage so their income lifts what the child can borrow, while the child is the sole owner. Because the parent does not own a share, the additional property stamp duty surcharge is not triggered by their involvement and the child keeps first time buyer status.
All borrowers’ incomes are assessed together, but only the proprietor’s name goes on the title at the Land Registry
The supporting borrower is fully liable without owning any of the property, and nearly always needs independent legal advice
It suits people with a deposit but not enough income, the opposite of the gifted deposit case
As featured in…
Meet your Advisor
Harry Goodliffe
- FCA Authorised
- Director & Mortgage Advisor
“I‘m not about confusing jargon or passing you from person to person. From our first chat to the day you get the keys, you’ll deal directly with me. I‘ll keep you updated, answer any burning questions, and do everything I can to make the whole process as stress-free as possible.”
Let’s Talk About Your Mortgage
How a JBSP mortgage is put together
1
Step 1
Income check
I assess the proprietor and the supporting borrower together, the same way as a joint mortgage. The gap between what the proprietor could borrow alone and what they need is what the supporting income has to cover.
2
Step 2
Relationship and age
Lenders vary on who can support (usually a close family member) and apply their normal maximum age at the end of the term to every borrower. A parent in their late fifties can shorten the term available, which pushes the monthly payment up.
3
Step 3
Legal advice
Most lenders insist the supporting borrower takes independent legal advice before signing, so they understand they are liable for a property they do not own.
4
Step 4
Removal later
Once the proprietor’s income can carry the loan alone, most lenders will remove the supporting borrower by way of a further application.
About
Our approach.
JBSP or guarantor mortgage?
A guarantor promises to step in if payments are missed and usually offers savings or their own property as security. They are not a borrower and their income is not part of the affordability calculation in the same way. A JBSP borrower is on the mortgage from day one and their income is counted in full. It is more direct, and more lenders offer it than true guarantor products. The stamp duty position is the reason JBSP exists: if a parent who already owns a home went on the deeds, the whole purchase would attract the additional property surcharge. Stamp duty rules change and this is a tax matter, so confirm your own position with your solicitor. The JBSP case I placed used a parent to boost affordability. The lender needed the father to evidence income that would continue into retirement, because the mortgage term ran past his retirement age, and that was the part of the case that took the most work.
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Whole-of-market comparison across 120+ lenders
One Flat Fee
A flat £350 fee, payable only once your mortgage offer is issued
Honest Advice
If the right answer is to do nothing, I will say so
Outside My Scope
I do not offer equity release
How I help
I work out whether the shortfall is income or deposit, which decides between JBSP, a gifted deposit or a guarantor route, then check which lenders accept the relationship and ages involved. The legal and tax points go to your solicitor. Related: no deposit mortgages and the first time buyer hub.
Who this is for
Buyers whose income falls a little short of what they need, with a parent or close relative willing to join the mortgage, and families where an adult child wants to support a parent’s mortgage the other way round.
Why use HTG’s mortgage services?
Monday to Friday 8am to 5pm, Saturday 8am to 1pm
We are an independently owned, whole-of-market mortgage broker offering first-charge mortgages
You deal with Harry directly, from the first conversation to completion
Let’s get your mortgage sorted
Written by Harry Goodliffe
Director & Mortgage Adviser, HTG Mortgages · FCA Authorised (1017945)
CeMAP Qualified · Featured in National Press · South England Prestige Awards 2026/27 winner