Who Can Be a Joint Borrower on a Joint Borrower Sole Proprietor (JBSP) Mortgage?
A Joint Borrower Sole Proprietor (JBSP) mortgage can make homeownership more accessible for people who may not be able to borrow enough on their own. By allowing additional borrowers to support the mortgage application without becoming legal owners of the property, this type of mortgage can help improve affordability while keeping ownership simple.
However, not everyone can act as a joint borrower. Lender criteria varies, so it’s important to understand who is typically eligible before you apply.
Who can be on a joint borrower sole proprietor mortgage?
At least 35 banks and building societies in the UK offer Joint Borrower Sole Proprietor (JBSP) mortgages (correct as of July 26). Most allow close family members to join the mortgage application. Some of the most common arrangements include:
- Parents helping adult children buy their first home.
- Grandparents supporting grandchildren.
- Adult children helping older parents in some circumstances.
- Siblings applying together, depending on the lender.
Some lenders may also consider other relatives or, less commonly, close friends. However, eligibility differs between lenders, and many restrict JBSP mortgages to immediate family members.
Because lending policies vary, speaking to a qualified mortgage adviser can help identify lenders whose criteria match your circumstances.
Does the joint borrower own the property?
We are often asked whether the joint borrower owns the property with this type of mortgage. The answer is no, and this is one of the defining features of a JBSP mortgage.
The sole proprietor is the only legal owner of the property and is the person whose name appears on the title deeds. The joint borrower is named on the mortgage agreement but does not automatically acquire legal ownership or rights to any increase in the property’s value.
This structure can be beneficial where family members want to help someone purchase a home without becoming co-owners.
What are the lender’s requirements?
While every lender has its own criteria, joint borrowers are usually expected to meet similar lending standards as the main applicant.
Lenders typically assess:
- Income and employment.
- Existing financial commitments.
- Credit history.
- Age.
- Overall affordability.
The joint borrower’s income is generally included when assessing how much can be borrowed, although each lender has its own affordability model and may apply different assumptions.
Both the sole proprietor and the joint borrower are usually jointly and severally liable for the mortgage. This means each borrower can be held responsible for ensuring the mortgage repayments are made.
Are there age limits?
Many lenders apply maximum age limits to JBSP mortgages, particularly where parents or grandparents are supporting the application.
For example, some lenders require the mortgage to end before the oldest borrower reaches a specified age, while others offer more flexible criteria for applicants with suitable retirement income.
If an older family member is acting as a joint borrower, it’s worth checking lender requirements carefully, as age limits can affect both the mortgage term and the amount available to borrow.
Can a joint borrower be removed later?
In many cases, yes this is doable. As the sole proprietor’s income increases over time, they may be able to remortgage into their own name and remove the supporting borrower. This will usually depend on meeting the lender’s affordability criteria at the time of the remortgage.
There may also be legal and administrative costs involved, so it’s sensible to discuss future plans before taking out the mortgage.
The bottom line
A Joint Borrower Sole Proprietor mortgage can be a useful option for buyers who need additional financial support to purchase a home, particularly first-time buyers with family assistance.
While parents are the most common joint borrowers, other relatives may also be accepted depending on the lender. As criteria varies significantly across the market, obtaining independent mortgage advice can help you understand your options and identify the most suitable lender for your circumstances.
Remember that a JBSP mortgage is a long-term financial commitment. Anyone considering becoming a joint borrower should ensure they understand their responsibilities and seek professional advice if they are unsure about the legal or financial implications.
Keen to see if a JBSP mortgage is right for you? Contact our expert advisers to get started.
Frequently Asked Questions
- Can my parents be joint borrowers without owning the property?
Yes. This is one of the most common uses of a Joint Borrower Sole Proprietor (JBSP) mortgage. Your parents can be named on the mortgage to help increase affordability without being added to the property’s title deeds. However, they’ll usually share responsibility for the mortgage repayments, and acceptance will depend on the lender’s eligibility and affordability criteria.
- Can friends or partners be joint borrowers on a JBSP mortgage?
Some lenders may consider applications from friends, siblings or unmarried partners, while others only accept close family members as joint borrowers. Each lender sets its own criteria, so eligibility can vary. A mortgage adviser can help identify lenders that may be suitable for your circumstances.
- Does being a joint borrower affect my ability to get another mortgage?
It can. As a joint borrower, you’re legally responsible for the mortgage, and lenders may take this commitment into account if you apply for borrowing elsewhere in the future. How it affects a new application will depend on factors such as the lender’s affordability assessment, your income and your existing financial commitments.

