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Booster Calculator

Need a little boost with your deposit? Maybe a family member can help. Or perhaps you’re looking to support  someone looking to take their first steps on the property ladder. 

How does it work?

  • The buyer has a property in mind but doesn’t have a big enough deposit.
  • A family member boosts the deposit by using their savings, income, or property. 
  • Only the buyer owns the property - the family member isn’t named on the mortgage or property deeds. 
  • Calculator results can be shared easily between family members. 

Go to Booster Calculator

What you need to know

The calculator has no impact on your credit score 

We won’t do a credit search. 

Results shown by the calculator are only an estimate 

You’ll need to complete an Agreement in Principle (AIP) to get an idea of how much we could lend you. 

You might get a different result to some of our other calculators 

We sometimes ask for more information on our other calculators to give a more accurate result. This could include things like your outstanding credit commitments or your employment status, for example. 

Think one of our standard mortgage deals might be right for you?

Try one of our other mortgage calculators.

Go to mortgage calculators

Already started your mortgage journey?

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What are your mortgage options?

Standard Mortgage

This is how much the buyer could borrow without any help from a family member.

Family Boost mortgage

This is where the family member puts 10% of the agreed property purchase price into a 3-year fixed term savings account with us.

Family Remortgage

This is where the family member remortgages their own property to release equity and help boost the buyer’s deposit.

Contact us

Got any questions? Get in touch with our mortgage experts.  


Call us on 0345 850 0248. Lines are open Monday to Friday 8am – 8pm and Saturday 9am – 4pm. We're closed on Sundays and bank holidays.

Or, you can book a branch appointment.

If you have a hearing or speech impairment, you can contact us using the Relay UK service. There’s more information on the Relay UK help pages. If you’re Deaf and a BSL user, you can use our BSL SignVideo service.

You could lose your home if you don’t keep up your mortgage repayments

FAQs

  • A booster is someone - usually a family member of the person looking to buy a property - who uses their savings, income, or equity from their own home to increase a deposit.

  • The Booster Calculator is for first-time buyers who don’t have a large enough deposit to put down on a property. They can add a family member’s savings, income, or property equity to boost the deposit, and get an idea of how much they can afford. The calculator will also give the buyer some mortgage options they might be eligible to apply for.

    Family members (boosters) can also use the calculator to see how they can support a buyer.

  • No. You can use all our mortgage calculators safe in the knowledge your credit score won’t be affected. We don’t do any credit checks at this stage. The calculators are just to give you an idea of what your repayments might be. If you apply for a mortgage, we’ll do a full credit check - this might impact your credit score.

  • This will depends on lots of things. We’ll do an affordability assessment, where we’ll review your details, including:

    • your income - salary, bonuses, and benefits
    • your existing credit commitments, like credit cards, loans, and store cards
    • any other outgoings and financial commitments, like childcare costs
    • how much deposit and/or equity you have
    • your credit rating.

    If you’re buying a house with another person, we’ll usually take their income into account when deciding how much you can borrow. Our mortgage calculators can give you a rough idea of how much you could borrow for your mortgage. You'll need to complete an Agreement in Principle (AIP) to confirm how much you could be eligible to borrow, before you apply for a mortgage. 

  • This calculator is designed to give you an idea of how much you could borrow by including a booster. Some of our other calculators ask you for other information, like other credit you owe. You’ll need to complete a full application to see how much we can lend you.