Joint Borrower, Sole Proprietor Mortgages: Who They’re For & When They Work

November 19th 2025

If you’re struggling with affordability on your own, you might have come across something called a Joint Borrower, Sole Proprietor (JBSP) mortgage. It’s a mouthful, but the idea is simple: someone else can help you borrow more, without owning any share of the property.

In this guide, we’ll break down how JBSP mortgages work, who they’re best for, and when they can be a smart solution.

What Is a Joint Borrower, Sole Proprietor Mortgage?

A JBSP mortgage allows an extra person (usually a parent or close family member) to go on the mortgage but not on the property deeds.

This means:

They share responsibility for paying the mortgage.
They don’t own any part of the home.
They’re not caught by the extra 3% stamp duty surcharge that applies to second-home ownership.

It’s basically a way to boost affordability without adding someone as a legal owner.

Why Would Someone Use a JBSP Mortgage?

To Increase Borrowing Capacity

If your income doesn’t stretch far enough on its own, a second applicant’s income can help you borrow more. This is especially common for:

First-time buyers facing high house prices
Single applicants
People with lower or inconsistent income

To Get on the Ladder Earlier

Instead of waiting to increase income, build savings or pay off debts, a JBSP mortgage can speed up the process.

To Avoid Family Members Owning Part of the Home

Parents often want to help, but don’t want to be tied to the property legally. JBSP works perfectly here.

To Avoid Stamp Duty Surcharge

If a parent went on the deeds, they may pay the additional 3% stamp duty. JBSP avoids this because the helper isn’t a legal owner.

Who Are JBSP Mortgages Ideal For?

JBSP is most commonly used by:

First-time buyers

Especially young professionals whose incomes haven’t caught up with house prices in their area.

Parents helping adult children

This is by far the biggest category. Parents can use their income to support the mortgage while the child owns the home.

Couples where one partner has lower income or credit issues

If one person can’t go on the mortgage (credit, affordability, past financial issues), they can still live in the property while the other partner and a helper apply.

Single parents

Where one income alone isn’t enough to meet lender affordability models.

Older borrowers

Sometimes adult children go on the mortgage to help parents downsize or move, though lenders vary on age limits.

How a JBSP Mortgage Works (Step-by-Step)

Borrower + helper(s) apply for the mortgage together.
Lender assesses all incomes, commitments and credit files.
Only the main buyer (the sole proprietor) goes on the property deeds.
The mortgage offer names all applicants, who share the legal responsibility for the loan.
Everyone must pass affordability, credit, age criteria and take independent legal advice.
Over time, the helper can often be removed from the mortgage when affordability improves.

Pros of a JBSP Mortgage

Boosts affordability significantly

Can help you borrow more than you could alone.

No extra stamp duty for the helper

Parents, siblings or partners help without owning part of the home

Flexible exit — they can come off later

Good for long-term affordability growth

Perfect for careers with strong income progression.

Cons to Consider

All borrowers are legally responsible for the full mortgage

If payments are missed, everyone’s credit file is affected.

Age limits can restrict mortgage terms

If the helper is older, their age may reduce the maximum mortgage term.

The helper’s borrowing may be affected

Their income is tied to this mortgage, which can limit their future applications.

Some lenders require legal advice

Independent legal advice is often mandatory for the non-owner borrower.

When Does a JBSP Mortgage Work Best?

When the main buyer’s income is rising

For example, early-career roles with strong salary progression.

When the helper has stable, strong income

Often a parent or relative with good credit and minimal debts.

When other options don’t fit

Such as when:

A guarantor mortgage isn’t available
A gifted deposit still isn’t enough
A partner can’t go on the mortgage

When avoiding stamp duty surcharge matters

A JBSP mortgage can work really well when one partner already owns a property and the couple want to buy a home together, but don’t want the existing property to trigger the additional 3% stamp duty surcharge.
Instead of adding the partner who already owns a property to the deeds, they can simply go on the mortgage to support affordability — avoiding the second-home tax charge.

**When JBSP Might Not Be Suitable**

If the helper wants to own part of the home → Joint mortgage may be better.
If the helper is near retirement → affordability may be restricted.
If the buyer’s income won’t realistically improve → removal later may be hard.
If multiple applicants already have commitments → affordability may still fall short.

Can the Helper Be Removed Later?

Yes — this is one of the best parts of JBSP mortgages.

Once the main borrower’s income improves, or once debts are reduced, you can request a remortgage or product transfer to remove the helper.

Is a JBSP Mortgage Right for You?

Every situation is different. A JBSP mortgage can be incredibly helpful for buyers who need extra support to get onto the property ladder, but it isn’t right for everyone.

Speaking with a broker gives you personalised guidance, checks lender criteria, and helps you choose the right solution for your circumstances.

Need Advice?

If you’d like to explore whether a JBSP mortgage could work for you, we’re happy to help.

Get in touch and we can run through your options, affordability and the lenders offering JBSP products right now.

In the challenging process of divorce, where emotions run high and futures feel uncertain, one aspect that often requires immediate attention is the division of assets, including the marital home. Whether you’re planning to retain the family home or looking to purchase a new one, obtaining a mortgage capacity report becomes crucial. But what exactly does this entail in the context of divorce in the UK, and how can you navigate this process successfully? In this guide, we’ll explore the significance of mortgage capacity reports in UK divorce proceedings, the role of debt-to-income ratios, and provide a roadmap for obtaining one.

The Role of Mortgage Capacity Reports in Divorce

During divorce proceedings in the UK, determining the future of the marital home is often one of the most contentious issues. In many cases, one spouse may wish to keep the home while the other seeks to sell it. If you intend to retain the family home, you’ll need to demonstrate to the court and your ex-spouse that you have the financial means to do so. This is where a mortgage capacity report comes into play.

Why It’s Important

Financial Clarity: Amidst the upheaval of divorce, having a clear understanding of your financial situation is essential. A mortgage capacity report provides insight into your borrowing power, helping you assess whether you can afford to keep the marital home or purchase a new one.
Negotiating Leverage: If you’re negotiating the division of assets with your ex-spouse, having a mortgage capacity report can give you leverage. It demonstrates to both your ex-spouse and the court that you are financially capable of maintaining homeownership, potentially influencing the outcome of asset distribution.
Planning for the Future: Decisions made during divorce proceedings have long-term implications. A mortgage capacity report empowers you to make informed decisions about your housing situation, ensuring that your post-divorce living arrangements align with your financial capabilities and goals.

Understanding Debt-to-Income Ratios

A crucial factor in determining your mortgage capacity is your debt-to-income (DTI) ratio. This ratio represents the percentage of your monthly gross income that goes towards paying off debts, including mortgage payments, credit card bills, and other loans. Lenders use DTI ratios to assess your ability to manage additional debt and determine the amount of mortgage you can afford.

How to Obtain a Mortgage Capacity Report in UK Divorce

Navigating the process of obtaining a mortgage capacity report during divorce in the UK requires careful planning and communication. Here’s a step-by-step guide to help you through the process:

Consult with a Divorce Solicitor: Before initiating the process of obtaining a mortgage capacity report, consult with a qualified divorce solicitor. They can provide legal guidance tailored to your specific circumstances and help you understand the implications of retaining or relinquishing the marital home.
Assess Your Financial Situation: Gather all relevant financial documents, including income statements, bank statements, tax returns, and any existing mortgage documents. Calculate your debt-to-income ratio to determine your borrowing capacity.
Research Lenders: Research mortgage lenders that specialize in divorce-related financing or have experience working with divorcing couples in the UK. Look for lenders who offer pre-approval services and are sensitive to the unique challenges of divorce under UK law.
Schedule a Consultation: Reach out to selected lenders to schedule a consultation. During the consultation, discuss your specific needs and circumstances, including your desired loan amount, interest rates, and any other pertinent information related to your divorce in the UK.
Complete the Application Process: Once you’ve chosen a lender, complete the mortgage pre-approval application process. Be prepared to provide detailed information about your income, assets, debts, and the property you intend to purchase or retain.
Undergo a Credit Check: As part of the pre-approval process, the lender will conduct a credit check to assess your creditworthiness. Your credit score plays a significant role in determining your eligibility for a mortgage and the terms of the loan.
Receive the Mortgage Capacity Report: If you meet the lender’s criteria, you’ll receive a mortgage capacity report outlining the loan amount you qualify for, the interest rate, and any conditions or contingencies that must be met.
Present the Report in Divorce Proceedings: Share the mortgage capacity report with your solicitor and present it as evidence in divorce proceedings in the UK. The report, along with your calculated debt-to-income ratio, will demonstrate your financial ability to retain or purchase a home, supporting your position during negotiations or court hearings.

Conclusion

In the complex terrain of divorce in the UK, obtaining a mortgage capacity report is a crucial step towards securing your financial future and achieving housing stability. By considering factors such as debt-to-income ratios and seeking guidance from legal and financial professionals, you can navigate the process with confidence and clarity. Remember to prioritize open communication, thorough documentation, and careful planning to ensure the best possible outcome for your post-divorce housing arrangements. With the right support and preparation, you can embark on this new chapter of your life with confidence and resilience.