Offset Mortgage
Plain-English definition of Offset Mortgage — part of our property glossary.
Definition
A mortgage linked to a savings account: interest is charged only on the mortgage balance minus the savings balance. Useful for people with substantial savings who still want mortgage leverage, because the offset savings effectively earn the mortgage rate tax-free.
Worked example
With a £250,000 mortgage at 5% and £30,000 of savings offset, interest is charged on just £220,000 — saving £1,500/year. Equivalent to your £30,000 savings earning 5% tax-free, with instant access maintained.
Why it matters
Property is the single largest financial transaction most households ever make, and small mistakes — a worse rate, a missed relief, the wrong structure — compound over 25–30 years. Fluent vocabulary is the difference between spotting a costly clause and signing it.
Common mistake
Assuming advertised rates apply to everyone. Loan-to-value bands, property type, and credit history all filter you into a narrower set of actual rates. Always price the deal for your specific LTV and property, not the headline teaser.
Calculators that use this concept
See also
- SDLT (Stamp Duty Land Tax) — Stamp Duty Land Tax is the UK tax on residential and commercial property purchases in England and Northern Ire…
- LTV (Loan-to-Value) — LTV is the mortgage amount expressed as a percentage of the property value. A £180,000 mortgage on a £200,000 …
- First-Time Buyer (FTB) — In UK property, a first-time buyer is someone who has never owned a residential property anywhere in the world…
- Help to Buy ISA (closed) — A government scheme closed to new entries in November 2019. Existing accounts still earn the 25% bonus on savi…
- Lifetime ISA (LISA) — A Lifetime ISA lets 18–39-year-olds save up to £4,000/year and receive a 25% government bonus on top, up to ag…