Guarantor Mortgage FAQ
General information only. This is not financial advice.
Last reviewed: 2026-06-06
How does a guarantor mortgage work?
A guarantor mortgage allows a third party — usually a parent or close relative — to support a mortgage application by agreeing to cover repayments if the borrower cannot. The lender assesses the guarantor's income and assets as secondary security. The primary borrower owns the property and is the main mortgage holder; the guarantor is only called upon if there is a default. Fewer lenders offer traditional guarantor products today, with most preferring joint borrower sole proprietor structures instead.
What is a joint borrower sole proprietor mortgage?
A joint borrower sole proprietor (JBSP) mortgage allows a second person — typically a parent — to be named on the mortgage to boost affordability, while only the borrower is registered on the property title. This means the supporting party does not acquire a legal interest in the property and may avoid the stamp duty surcharge on second homes (depending on their circumstances). JBSP is now the preferred structure at most specialist lenders.
What are the risks for a mortgage guarantor?
A guarantor takes on full legal liability for the mortgage debt if the borrower defaults. This can damage the guarantor's credit score, restrict their ability to borrow for their own purchases, and in worst-case scenarios, lenders may pursue the guarantor's own assets. Guarantors should always take independent legal advice before signing and consider whether a JBSP or family springboard mortgage would better suit their situation.
How does a family springboard mortgage work?
Family springboard mortgages allow a family member to deposit savings — usually 10% of the purchase price — into a savings account held as security against the mortgage. If the borrower maintains all repayments over a set period (typically three to five years), the savings are returned to the family member with interest. Unlike a traditional guarantee, the liability is limited to the deposited funds and does not create an open-ended personal obligation.
Can a guarantor be removed from a mortgage?
Yes, but it requires the lender's agreement. The borrower typically needs to demonstrate that their income alone is sufficient to support the mortgage — either because their salary has increased or the mortgage balance has reduced. A formal reassessment of affordability is carried out, and if approved, the guarantor is released. This process usually takes three to five years, depending on income growth and property equity.
What documents does a guarantor need to provide?
Guarantors are usually asked to provide proof of identity, recent payslips or self-employed accounts, three to six months of bank statements, details of existing debts and commitments, and sometimes a mortgage or rental statement for their own home. The lender assesses the guarantor's disposable income after accounting for their own outgoings to confirm they could service the debt if called upon.
Risk warning
Your home may be repossessed if you do not keep up repayments on your mortgage. Think carefully before securing other debts against your home. This article is general information only and does not constitute financial advice.
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