Increase the amount you can borrow with an Income Boost

What is an Income Boost mortgage

An Income Boost mortgage, also known as Joint Borrower Sole Proprietor (JBSP) mortgage is a way of adding some or all of a family member or friend's income to a mortgage to increase the buyer's max borrowing. Unlike standard joint mortgages the additional borrower will not own the property or be named on the deeds.

How a Tembo Income Boost works

So you need to close the affordability gap

You’ve got a healthy enough deposit saved, but you can’t borrow enough to buy your dream home. It’s an all too common story.


Affordability gap

Max borrowing alone


Time to tag in a booster

With an Income Boost, an eligible booster can add some of their income to your mortgage to fill the affordability gap. They will have no ownership over the property, but will need to help with repayments if required.

You’re all set to get that dream home

With your booster onboard and the affordability gap gone, we’ll scan the whole market to broker you a Joint Borrower Sole Proprietor (JBSP) mortgage with the additional income.


Check if you're eligible for an Income Boost

Get started

Income Boost Calculator

See how much you increase your borrowing by adding an Income Boost to your mortgage.

Lenders will currently let buyers borrow around 4.5x income, and average house prices sit at 7.5x income.

Budget with Booster


£720 per month

Budget on your own



The benefits of using an Income Boost

Buy the home you really love

By combining up to four income sources, an Income Boost can significantly increase a buyer's borrowing potential. So there's no need to compromise on your dream home or your dream location.

A stepping stone to doing it alone

An Income Boost is a temporary support for buyers as they are getting onto the property ladder. When your circumstances change (i.e you get a pay rise), the Booster can come off the mortgage!

Your family won't be out of pocket

With an Income Boost there's no need for a Booster to dip into cash savings or investments to help their buyer. They won't be on the deeds of the property, meaning there's no stamp duty liability.

Check your eligibility

Risks & considerations

As with all loans and mortgages, it's important to understand the potential risks and eligibility criteria when considering using an Income Boost, known as a Joint Borrower Sole Proprietor mortgage.

Things to consider...

  • The Booster and the buyer will have to pass a credit check

    All borrowers on the mortgage application will need to pass a credit check. If the Booster is overcommitted with their borrowing and outgoings (for example, the Booster’s own mortgage is too big), they may not be eligible for a JBSP mortgage.

  • Everyone on the mortgage is jointly liable for the monthly payments

    It is important to note that all those named on a JBSP mortgage application are ‘jointly & severally liable’ for the monthly mortgage payments. If no one makes those payments, this will affect the credit history of all those named on the mortgage application.

  • The Booster will not have any legal rights to the property

    All those named on the mortgage application will be liable for repaying the mortgage. However, only the homeowner has any rights to the value in the property. So parents or relatives who put their income at risk in this way will have no rights to the property.

Why Tembo?

We're making it possible for you to buy a home.

Interest rates start from 0.85%

We work from a comprehensive panel of lenders that are representative of the whole of the market. This could get you the best interest rate going on your mortgage.

Secure and trusted

Tembo is authorised and regulated by the FCA. Plus, we're backed with investment from leading names in finance including Aviva and Nationwide.

First-time buyer specialists

Our qualified mortgage experts are trained to make your homeownership dreams happen. In fact, over 70% of our users couldn't buy their home without using a family Boost.

Thousands of buyers have used Tembo to discover how a family Boost could make their next move happen.

Read our reviews to find out why our customers rate us as 'Excellent' on Trustpilot.

“Friendly, efficient, helpful, what more can you ask for? My daughter & I used an Income Boost enabling her to buy her first home. Without Tembo, she would not have been able to buy. As a parent I was able to provide support & feel fully confident.”




“My mum came across Tembo and we managed to speak to a broker the next day. The additional budget we get from the Income Boost is a game changer in our property search. It means we can buy in the area we want to. Thank you Tembo!”



First-time buyer

“Best decision my wife and I made was to use Tembo to purchase our first house. They sorted a mortgage out for us in approximately a month and a half, with ease. Brilliant! I would 100% use them again and would recommend them to anyone.”



First-time buyer

“Our daughter found a house but there was a shortfall in what she could borrow. There was a few weeks of panic and we came across Tembo. They arranged a JBSP and she got the house. So happy to have been able to help our family. ”

Mrs G-avatar

Mrs G


Some folks who have gone before you.

Read on to discover how we've helped other buyers onto the ladder.

Meet Tim

Read his story

Meet Stella and Pieter

Read their story

Meet The Fosters

Read their story

Hungry for more information?

A Boost is a way for family or friends to help you get on the ladder. If you need help explaining Tembo to your loved ones, download our handy guide. Or, if you'd like to see the proof behind the claims we've made here, check out our transparency page.