Mortgage tools
Guarantor and JBSP mortgage calculator
Yes, a family member can help you borrow more, and you can see roughly how much more in a few seconds. Enter your income and your helper's income below, and this tool shows what you might borrow on your own next to what you could borrow with them added on a Joint Borrower Sole Proprietor (JBSP) basis.
The reason a helper lifts the figure is simple: the lender assesses your combined income rather than yours alone, usually at 4.5 to 5 times that income. On a JBSP mortgage your helper supports the borrowing without going on the title, so you stay the sole owner. This calculator puts the two figures side by side so the difference is plain before you ever speak to a lender.
If more than one person is helping, add their incomes together.
Your indicative borrowing range
Enter your figures above
On a JBSP mortgage your helper supports the borrowing but is not on the property title. You stay the sole owner, and because they do not own a share, they avoid the extra stamp duty that applies to a second property.
A guarantor mortgage is similar but uses your helper as a financial backstop rather than a named borrower. Most lenders now offer JBSP, and the right one depends on your helper's age and income.
The term can be shorter where an older helper is involved, as some lenders work to their retirement age, which would reduce the figure. Their own mortgage and outgoings also affect how much they can add.
Figures are illustrative. Lenders differ on income multiples, how they treat a helper's age and outgoings, and whether they offer JBSP or guarantor terms. Your actual borrowing depends on the lender's assessment and your full circumstances.
These figures are illustrative only. They are not a quote, offer or advice. Actual borrowing is subject to full lender assessment and status.
See how much a helper could add to your case
Check Your EligibilityThink carefully before securing your debts against your home. Your home may be repossessed if you do not keep up repayments on your mortgage.