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Income Boost

Help your loved ones get a home of their own by using your income.

Income Boost

Help your loved ones get a home of their own, without handing over any savings. Support their mortgage by adding some or all of your earnings to their household income, helping them to increase their maximum borrowing potential.

The team at Saga Mortgages, provided by Tembo, can walk you through the steps of becoming an Income Booster, and help you work out if it’s the right option for you and your family.

How does it work?

An Income Boost is a type of guarantor mortgage which works by adding some or all of your earnings to a loved one’s household income to a mortgage application. This can help them get a larger mortgage loan, allowing them to get on the ladder sooner, buy in the location they love or even afford a larger property.

Also known as Joint Borrower Sole Proprietor mortgage (JBSP), an Income Boost is a great way for family members or friends to help the next generation overcome the growing mortgage affordability gap, without giving any money.

You will be classed as a borrower on the mortgage, meaning you’re jointly liable for the mortgage debt. This doesn’t mean you need to financially support the buyer’s monthly repayments, unless they default, in which case you will be required to step in. 

However, you’re not a co-owner of the property, and your name isn’t listed on the deeds. This means there aren’t any tax implications for supporting the buyer, for example, your support wouldn’t affect any first-time buyer relief the buyer might be eligible for. 

Later down the line if your loved one’s affordability improves, for example they’ve had a pay rise, or built up equity in the home, they can remortgage to switch over to a standard repayment mortgage, removing you from the mortgage.

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Knowing your mortgage options

Saga Mortgages can help you understand and navigate your mortgage options.

Finding out which products are available starts with knowing which ones you're eligible for and we can help with that.

Am I eligible?


  • Help your loved one buy or remortgage. The average house in the UK currently costs around 11 times average earnings. But most lenders will only allow borrowers to borrow between 4 to 4.5 times their income. This leaves a substantial affordability gap for the next generation of home buyers. Through an Income Boost, you can help your loved one increase the amount they can borrow for a mortgage, helping to bridge the gap.
  • You don't need to use cash or investments. Because you are using your income as security, with an Income Boost you will not need to give your loved ones any cash savings or investments to support their mortgage. As long as they make their mortgage repayments each month, you will not need to contribute to the home financially.
  • Your support can be temporary. When your loved ones can afford the mortgage by themselves, you can be removed from the mortgage. In this way, an Income Boost can be used as a temporary ‘leg up’ to help your loved ones get on the ladder sooner.
  • There are no tax implications. Because you won’t be listed on the deeds of the home, your loved one’s stamp duty relief as first time buyers won’t be impacted by your support. Plus, your tax position won’t be affected by supporting the mortgage either.

Risks and considerations

  • You'll be liable for the mortgage debt. Although you are not named as an owner of the property, you will be named on the mortgage. This means you are liable for repaying the loan alongside the borrowers, but only the homeowner has any rights to the value in the property. This means if your loved one misses any of their mortgage repayments, you will be required to step in. Even if you do help your loved ones keep up with their mortgage payments, you will not have any rights to any equity in the home.
  • Your age could impact the borrower’s monthly repayments. Mortgage products have an age limit that the oldest borrower can be when the mortgage term has ended. If you are over the age of 60, this will reduce the mortgage term that your loved one will be offered, which will make the monthly repayments more expensive.
  • All applicants will undergo full affordability checks. A lender will need to ensure the mortgage is affordable before approving your loved one’s application. To do this, they will assess the affordability of all applicants. This means you will need to provide evidence of your income, expenses and identification. Even if you are a high earner, if you have overcommitted on your own borrowings and outgoings (for example, if you have a large outstanding mortgage or credit card debts) you may not pass a lender’s affordability assessment.
  • Your credit score could be impacted. Alongside your loved one, your credit rating will also be assessed by a lender before the mortgage loan can be approved. Because you are named on the mortgage, if your loved one misses any repayments this could also impact your credit rating, too.

Here and ready when you are

Whether you have questions about Income Boost mortgages or just want to find out more, the expert team are on hand to help.

0330 018 3071

Mon-Thu 9am-8pm
Fri 9am-5:30pm
Sat-Sun 10am-3pm

Am I eligible?

Frequently asked questions

Here are some of our most frequently asked questions
What is a Joint Borrower Sole Proprietor mortgage?

A Joint Borrower Sole Proprietor mortgage is another name for an Income Boost. It is a specialist type of family-support mortgage that allows a family member or friend to help a buyer or homeowner increase their mortgage affordability by adding your income to theirs on a mortgage application.

Widely considered to be a ‘next-generation’ guarantor mortgage, this product can be a great option if you want to help a loved one get on the ladder without giving them money, especially if your loved one is on a low salary which is limiting their ability to get the loan size they need to buy. 

Only the home buyers will have any rights to the property (they are the "sole proprietor"), but you will be named on the mortgage as a "joint borrower", which means you will be liable to pay the mortgage if your loved one cannot.

Who is eligible for an Income Boost?

To qualify for an Income Boost mortgage, the guarantor will need to meet the age requirements. This is because the length of the mortgage term is determined by the age of the oldest person named on the application. Most lenders require the mortgage loan to be paid off by the time the oldest borrower is 75 or 80.

A few lenders will extend beyond this, but if you’re over the age of 60, it’s likely the repayments could become more expensive. 

Alongside the buyers, guarantors will also undergo an affordability assessment. This includes assessing your income, outgoings, credit rating as well as proof of identification.

What sources of income will be considered?

Various types of income sources will be considered when assessing applicant's eligibility for an Income Boost. Both pension and employed income can be included, along with any other income, for example buy-to-let.

However, you will have to provide evidence of each source. For example, if you’re self-employed, you may have to supply up to 2-3 years worth of accounts to evidence your earnings.

How many people can be on an Income Boost mortgage?

Up to four people can be named on an Income Boost mortgage. So if you want to help your child and their significant other buy their first home, you and your partner could both be added onto the mortgage application.

What's the application process?

For the most part, the process of applying for an Income Boost is not dissimilar to that of a standard residential mortgage or remortgage. 

Once you’ve completed a Saga Mortgages recommendation, you’ll be invited to book an appointment and begin the advice process. If you decide an Income Boost is a good fit for you and your family, we’ll complete a full qualification for all applicants. This includes verifying your income, outgoings, identity, and credit history.

Your dedicated mortgage advisor will take you and your loved one through the options available from our panel of over 100 lenders, and once you’ve chosen a suitable product, we’ll submit the application for you. 

Note that it is a condition of the terms of these mortgages that you – as a joint borrower with no ownership rights - take independent legal advice. This is to ensure you’re willingly entering into the agreement and understand the implications. 

Will my loved one be able to make the repayments?

Because the mortgage is based on you and your loved one’s income, you might be worried that the repayments could be unaffordable for them. With an Income Boost set up, the lender will check both you and your loved one’s affordability to ensure that the loan is affordable.

Plus, it’s important to remember that for most young people, they are used to paying rent which takes up a similar amount of their earnings that a mortgage would. For example, monthly repayments for the average property, which costs £291,000, would cost £1,248*.

The average salary is £34,000, which means that these mortgage costs would take up 44% of their monthly pay before tax. While the average rent in the UK costs £1,275 each month, making up 45% of their monthly pre-tax earnings.

However, if you’re concerned about their ability to make the repayments and you don’t wish to contribute towards them, you should think very carefully about taking out an Income Boost and seek independent advice. 

*Based on 85% LTV, with a 35 year mortgage term and 5% mortgage interest rate.

Is there a maximum age?

Most lenders require the mortgage loan to be paid off by the time the oldest borrower is 75 or 80 years old, although some lenders extend beyond this. This means that if you are over the age of 60, your age is likely to make the repayments more expensive for your loved ones.

If you are over the maximum age requirements, it’s worth considering alternative ways to support your loved one’s home purchase. 

Are there other ways I could support my loved one’s purchase?

Yes, there are various ways you can support your loved one’s home purchase. For example, if you want to help bolster their house deposit, you can use a Deposit Boost, Savings as Security mortgage or even downsize or remortgage your property to release equity from it.

You could also direct them to an expert in mortgage affordability like the team at Saga Mortgages, who can help them discover ways they can boost their buying budget, with or without family support. Or allow them to move into your home and pay a small amount of rent, enabling them to save up a house deposit of their own sooner.

Can I be removed from the mortgage?

Yes, a guarantor can be removed from the mortgage if the other applicants are able to afford the mortgage on their own.

In this way, an Income Boost can be used as a short-term solution to help younger buyers get on the ladder sooner. When they can afford the property alone, they would simply need to remortgage the property and remove your name from the mortgage.

What happens if I retire?

If you plan to retire in the next few years, or you’re approaching retirement age, you’ll need to be able to evidence what your future pension income will be. 

What happens if one of the borrowers dies?

In the event of a guarantor passing away, the homeowner will need to go through another mortgage affordability assessment to determine if they can afford the mortgage on their own. If they are unable to afford the loan by themselves, they may have to sell the property.

Why choose Saga Mortgages?

Saga Mortgages is a service created to better support those over 50 looking to take out a mortgage. You’ll benefit from Tembo's award-winning advice from their friendly, experienced team of mortgage professionals, who are available seven days a week. They’ll search all the available options to find the best solution for you and your family.

When it comes to Income Boost and family support mortgages, Saga Mortgages has particular expertise. The service is provided by Tembo, a digital mortgage broker who specialise in boosting affordability using guarantor mortgages, and other specialist schemes. 

To understand how an Income Boost could work for you and your family, create a Saga Mortgages recommendation. This shows you indicative monthly repayments, live interest rates and product explainers for this and other guarantor schemes. Complete our short fact find to begin.  

Can I talk to an advisor?

The Saga Mortgage service enables you to book an appointment with award-winning mortgage advisors. Simply complete our online fact find and, if you’re eligible, you’ll be directed to book an appointment.

The team is available 7 days a week, ready to answer any questions you may have about Income Boost mortgages.

What lenders will you get access to?

With Saga Mortgages, you will have access to mortgage advice through our partner Tembo. Their award-winning mortgage advisors will search over 20,000 mortgage products and over 100 lenders to find the most suitable and best priced deal for you.

This includes all the high-street lenders you’ll be familiar with, like Nationwide, Halifax, Lloyds, Barclays and HSBC, as well as smaller, specialist lenders like Livemore and Generation Home.

Is Saga Mortgages FCA regulated to give mortgage advice?

All mortgage advice through Saga Mortgages is provided by Tembo Money Limited, who are regulated by the Financial Conduct Authority (FCA) under the registration number 952652. Their team of award-winning mortgage advisors are experienced in providing mortgage advice, including guidance on remortgaging, family supported mortgages and later life lending.

Important information

Saga Money may receive payment from Tembo if you obtain a mortgage offer through the Saga Mortgages service. This will not impact the amount you pay for the service.

Saga is a registered trading name of Saga Personal Finance Limited, which is registered in England and Wales (company number 3023493). Registered office 3 Pancras Square, London, N1C 4AG. Saga Personal Finance Limited is authorised and regulated by the Financial Conduct Authority under the registration number 178922. Tembo Money Limited (12631312) is a company registered in England and Wales with its registered office at 18 Crucifix Lane, London, SE1 3JW. Tembo is authorised and regulated by the Financial Conduct Authority under the registration number 952652. Tembo Money was awarded Best Mortgage Broker at the British Banking Awards in 2022 and 2023.