Income Booster mortgage

What is an Income Booster/Joint Borrower Sole Proprietor mortgage?

Our Income Booster, also known as Joint Borrower Sole Proprietor (JBSP), allows you to add up to three extra people onto a mortgage, without making them a legal owner of the property. We factor in all the incomes during the application, meaning you could borrow more than if you were taking out a mortgage on your own. 

Income Booster is a joint mortgage, so all borrowers will share the legal responsibility for paying the mortgage.

"A fantastic way to support would-be first-time buyers

Our Skipton Group Home Affordability Index 2025 research shows that 98% of adults living with parents still can’t afford to buy the average first-time buyer home in their local area, based on their own financial situation. And if they could, over 93.7% would face essential housing costs that exceed 45% of their income. Whether we call it Income Booster, Joint Borrower, Sole Proprietor, or JBSP, what’s clear is this could be a way for parents, guardians, friends or family to support buyers, and tackle the affordability challenges faced when getting onto, or moving up the property ladder.”

Jennifer Lloyd
Head of Mortgage Products and Proposition

How does an Income Booster work?

By including more people on your mortgage, you could borrow a higher amount. This is because your income will be assessed along with the income of your friends or family.  

It could be the extra boost you need to get onto, or move up, the property ladder. 

Our Income Booster isn’t just for first-time buyers, it’s also available for re-mortgages and new purchases. The Income Booster can be used with any of our standard residential mortgages. Although you need a deposit of at least 5%.

• There are no restrictions around the relationship between you and your supporting borrowers. This means we accept friends as well as family.

• In total, we could accept up to four applicants and up to all four incomes.

• The main borrower(s) must live in the property.

• All supporting borrowers must get independent legal advice before applying.

You can agree with your additional borrowers whether they need to contribute to regular repayments. However, all parties need to be aware that they will be liable to make any repayments if you are unable to.

How do I apply?

1. Call our friendly mortgage team who can check your affordability and arrange a Decision in Principle (DIP). A DIP gives an indication of how much you could borrow from us.
2. If your DIP is approved, we’ll arrange a mortgage advice appointment for you, either over the phone or by our  Video Appointment service – Skipton Link.
3. During the appointment, your dedicated mortgage adviser will recommend a suitable mortgage from our range. They can also prepare your full application.
4. We’ll answer any questions you might have. And at the end of the appointment, we'll take you through all the documentation and next steps for application. 

What are the benefits?

Increase your borrowing power

With up to four income sources taken into consideration, you could have a better chance of climbing onto, or up, the property ladder. That’s because it will increase how much you could borrow to buy a home. 

Additional borrowers can be removed in the future

Your additional borrowers are there to help you as a ‘stepping stone’ into your home. But if you can afford the property on your own, they can be removed from the mortgage (subject to passing our affordability checks). You can only do this once you reach the end of the initial mortgage deal period.

No difference to first-time buyer stamp duty relief

Your additional borrowers won’t be listed on your home’s deeds. So any eligible first-time buyers’ stamp duty relief won’t be affected. Neither will your mortgage’s tax position.

What do I need to consider?

The age of your additional borrowers could impact your repayments

Your mortgage term will be capped, based on the age of the oldest income-providing borrower. 

For example, the maximum age limit for anyone to finish paying their mortgage is usually 75.

Let’s say your eldest supporting borrower is 65. The longest mortgage term we might be able to offer is 10 years.

Everyone on your mortgage is liable for the debt

If the regular repayments aren’t made in full and on time, everyone’s credit history could be affected. The occupier could also risk losing their home.

We’ll need to complete affordability checks for everyone

As part of your application, we’ll complete a full assessment for all borrowers. This includes proof of income, outgoings, identification, and a credit check. This is all to check the mortgage is affordable for all applicants.

The Income Booster isn’t available with:

• Second Home purchase
• Discounted or Family Purchases
• Buy to Let
• Any other lending schemes (for example Shared Ownership)

Legal advice for additional borrowers

The people who are supporting the mortgage (known as non-proprietors) will be required to get independent legal advice.

Frequently Asked Questions

Other ways to get on the property ladder

If an Income Booster mortgage is not right for you, we have a range of other types of mortgages.

Legal Disclaimer

The Skipton Group Home Affordability Index is not a benchmark for the purposes of UK Benchmark Regulation, nor for the purposes of any other legislation or regulation. The Skipton Group Home Affordability Index is produced for information purposes only and must not be used or relied upon for commercial purposes or property related decisions. We are not responsible for any decisions made based on this information.