Choosing between a fixed-rate and a tracker mortgage is one of the fundamental decisions every UK borrower faces, and it comes down to a trade-off between certainty and potential savings. Here's a clear breakdown of how each works.
Fixed-rate mortgages
A fixed-rate mortgage locks your interest rate for an agreed period — commonly 2, 5 or occasionally 10 years — regardless of what happens to the Bank of England base rate or wider market rates during that time. Your monthly repayment stays the same for the whole fixed period, giving you budgeting certainty.
Pros
- Predictable monthly payments make budgeting straightforward
- Protection if interest rates rise during your fixed term
- Peace of mind, particularly valuable for first-time buyers adjusting to homeownership costs
Cons
- You won't benefit if interest rates fall during the fixed term
- Early Repayment Charges typically apply if you leave before the term ends
- Rates are sometimes slightly higher than a comparable tracker at the point of taking out the deal, reflecting the lender's own risk in offering rate certainty
Tracker mortgages
A tracker mortgage's interest rate moves directly in line with a specified external rate — almost always the Bank of England base rate — plus a fixed percentage margin set by the lender. If the base rate rises, your rate and repayment rise; if it falls, so do you.
Pros
- You benefit immediately if the base rate falls
- Often more transparent — the margin above base rate is clearly stated and moves predictably with published rate changes
- Many tracker deals have lower or no Early Repayment Charges, offering more flexibility to switch
Cons
- Your repayments can rise — sometimes significantly and with little notice — if the base rate increases
- Harder to budget precisely, since your payment isn't fixed
- Can be stressful during periods of rising or volatile interest rates
Side-by-side comparison
| Fixed-Rate | Tracker | |
|---|---|---|
| Payment certainty | High | Low — moves with base rate |
| Benefits from rate cuts | No (until the fix ends) | Yes, immediately |
| Exposed to rate rises | No (during the fix) | Yes, immediately |
| Typical ERC | Usually applies during term | Often lower or none |
| Best suited to | Borrowers prioritising certainty | Borrowers comfortable with variability, or expecting rate cuts |
How to decide between them
Consider your personal risk tolerance and financial buffer first: if a sudden rise in your monthly payment would cause real financial strain, a fixed rate's certainty is usually the more prudent choice regardless of which option is marginally cheaper today. If you have a comfortable financial cushion and a view (however uncertain) that rates are more likely to fall than rise over your chosen term, a tracker could work in your favour.
Don't forget discount and variable options
Fixed and tracker aren't the only two choices — discounted variable rate and standard variable rate mortgages also exist, each with their own trade-offs. See our guide to discount and SVR mortgages for the fuller picture.
For more on this, see our guide on Offset Mortgages Explained: How They Work.
Our free Mortgage Overpayment Calculator can help you check this against your own figures.
The bottom line
There's no universally "right" answer between fixed and tracker mortgages — it depends on your appetite for risk, your financial buffer, and your honest view of where interest rates might be heading. What matters most is understanding exactly what you're signing up for, including any Early Repayment Charges, before you commit.