For most people, a mortgage is the only way to buy a home — property prices are simply too high to pay cash. Understanding how mortgages work isn't just financially useful; it can save you tens of thousands of pounds over the life of the loan.
How mortgage repayments are structured
Each monthly payment contains two components: interest (the cost of borrowing) and capital (reducing the amount you owe). In the early years, most of your payment goes to interest. Over time, the balance shifts — you pay less interest (because you owe less) and more capital.
Types of mortgage rates
| Type | Rate changes? | Best when |
|---|---|---|
| Fixed rate (2–5yr) | No — stays same for term | Rates expected to rise; you want certainty |
| Variable / tracker | Yes — moves with base rate | Rates expected to fall; you can absorb risk |
| Offset | Varies | You have significant savings to offset |
Loan-to-value (LTV) — why your deposit size matters
LTV is the loan amount as a percentage of the property's value. A £200,000 home with a £40,000 deposit (20%) has an LTV of 80%. Lower LTV = better interest rates, because the lender's risk is lower. The difference between a 95% LTV and an 80% LTV mortgage can be 1–2 percentage points — on a £200,000 loan that's thousands of pounds per year.
What this means for you
Three decisions matter most: (1) Save as large a deposit as possible — each percentage point of LTV reduction saves significantly. (2) Overpay when you can — even small extra payments in the first decade dramatically reduce total interest paid, because they reduce the principal that interest is calculated on. (3) Remortgage when your fixed term ends — rolling onto a lender's standard variable rate can add thousands per year unnecessarily.