Answers · UK 2025/26

What is a family offset mortgage?

A family offset mortgage lets a family member (such as a parent) place their savings into a linked account to offset against a relative's (such as a first-time buyer child's) mortgage, reducing the interest the borrower pays, without the family member gifting the money outright or acting as a traditional guarantor. The family member's savings remain their own money and continue to be accessible, but they earn no interest on the linked balance while it is offsetting the mortgage.

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Family offset mortgages have become a popular way for parents and other family members to help younger relatives get onto the property ladder without permanently giving away a lump sum or taking on full guarantor liability. **How a family offset mortgage works** A family member (commonly a parent) deposits savings into an account linked to the borrower's mortgage, similar to a standard offset mortgage arrangement, but held in the family member's own name rather than the borrower's. The mortgage interest is calculated on the mortgage balance minus the linked savings balance, reducing the interest the borrower pays, while the family member's money remains legally theirs. **Benefits for the family member providing savings** Unlike gifting a deposit outright, the family member does not permanently give up the money -- it remains in their name and, depending on the specific product, may still be accessible if genuinely needed (though some products restrict withdrawals or require notice), and it is not swallowed into the property's equity in the way a gifted deposit would be. **The trade-off: no interest earned on the linked savings** While the savings are offsetting the mortgage, the family member typically earns no interest on that linked balance -- the "return" they receive is indirect, in the form of the borrower paying less mortgage interest, rather than direct interest paid to the family member's savings account. **How this differs from a guarantor mortgage** A guarantor mortgage requires the guarantor to commit to covering mortgage payments if the borrower defaults, creating a genuine ongoing legal liability. A family offset mortgage does not typically create the same direct liability -- the family member's exposure is limited to the savings balance they have chosen to place in the linked account, which they retain ownership of throughout. **Enabling a smaller deposit or better rate** Some family offset mortgage products allow the borrower to access a smaller headline deposit requirement, or a better interest rate band, than they could achieve alone, because the linked family savings effectively reduce the lender's risk on the loan, even though the family savings are not literally part of the borrower's deposit. **Worked example** A parent places £30,000 of savings into a family offset account linked to their child's £200,000 mortgage. The child's mortgage interest is calculated on the net £170,000 balance, reducing their monthly interest cost, while the parent's £30,000 remains their own money, earning no interest while offsetting but not permanently given away. **Practical tip** Use the Offset Mortgage calculator to estimate how much interest the borrower could save based on the family member's planned linked savings balance, and discuss access terms and any withdrawal restrictions carefully with the lender before committing, since products vary in how flexible they are.