A few years ago, when I spoke to brokers about joint borrower sole proprietor (JBSP) mortgages, the same reaction would come up time and time again: “It’s only really useful for parents helping kids, isn’t it?”
Look at it today, and that perception hasn’t shifted much. This is despite the fact the market around us has changed.
Rising property prices, longer mortgage terms, and affordability challenges have made family support more vital than ever. The average first-time buyer deposit is now over £61,000. Meanwhile, there has been a spike in first-time buyer completions earlier this year, likely fuelled by changing stamp duty thresholds. But affordability remains a hurdle. Terms are getting longer and payments as a share of income remain high.
At the same time, a growing number of young adults are living at home. Almost three in ten people aged 20 to 34 were still living with their parents in 2024. That figure was just over a quarter ten years ago. The trend is very clear. More families are leaning on each other, whether they intended to or not.
JBSP: more than just parents helping kids
The ‘Bank of Mum and Dad’ still plays a big role, but it’s far from the whole picture.
We’re increasingly seeing JBSP used in more varied, more complex, and frankly more relatable situations. We recently worked on a case involving a couple going through a separation. The JBSP route allowed one partner to retain the family home with the support of an adult child added to the mortgage. It gave stability to the household and avoided a forced sale during a tough time.
In another case, we saw friends use JBSP to combine incomes and buy together in London. It was a joint step onto the ladder that simply wouldn’t have been possible through standard affordability routes.
The common thread? These borrowers didn’t fit neatly into the traditional lending categories. But they had a real need and a workable solution. That’s where JBSP quietly does its job.
Flexibility isn’t just a nice-to-have
Another misconception I come across is the belief that JBSP must always be restricted by the age of the oldest borrower. But that’s not always true.
At Hinckley & Rugby, we offer split terms. This means affordability can be assessed based on the younger borrower’s age, giving far more flexibility than brokers might expect. A parent in their late 50s might assume they can’t help their child because it would shorten the mortgage term too much. With split terms, that assumption no longer holds.
It’s a simple tweak that can make a world of difference in practice.
If it’s so useful, why don’t more people know about it?
The problem, in many cases, is visibility. JBSP doesn’t always show up clearly in sourcing systems, so brokers may never see it appear as an option. That lack of visibility keeps it feeling niche or specialist, even when it could be a mainstream solution.
That’s part of the reason why we integrated JBSP into our core mortgage range earlier this year. We didn’t want it sitting in a separate box on the shelf. We wanted it right there with the rest of our residential lending, because that’s exactly where it belongs.
But it’s not just about product positioning. It’s about familiarity. If a broker hasn’t placed a JBSP case before, they may not know where to start. If clients haven’t heard of it, they won’t ask for it. That’s where open conversations, and case studies like the ones above, are really relevant.
The wider market context is changing fast
The average loan-to-income ratio for first-time buyers is still sitting at 3.6. This is a clear sign that affordability is tight. In parallel, multigenerational households are becoming more common, and income is no longer flowing from a single, stable source.
JBSP is one way lenders can keep pace with this. It’s not about pushing borrowing to the limit. It’s about reflecting the financial realities people are already living with. Shared responsibility, shared income, and shared ambition.
Time to shift the perspective
If JBSP still feels underused, it’s not because it’s irrelevant. It’s because the full picture hasn’t been drawn clearly enough.
The product is available. The criteria are often more flexible than assumed, and the range of client scenarios it can support is far broader than just ‘mum and dad helping out’.
As brokers, you don’t need to wait for a client to ask about JBSP specifically. Sometimes, it’s about reading between the lines and recognising where it could be a good fit.
This article is the first in a new Shifting Perspectives series designed to challenge assumptions. JBSP isn’t a niche product. It’s a flexible framework. And when we start seeing it that way, it becomes a powerful tool to help clients who might otherwise be stuck in limbo.
