A fixed-rate mortgage and a tracker mortgage solve different problems. Fixed rates are about certainty. Trackers are about flexibility and rate movement. The right choice is not the one with the lowest headline rate today; it is the one that still works if rates move differently from what you expected.
If your budget would struggle after a rate rise, certainty may matter more than chasing a lower starting payment. If you have spare monthly capacity and believe rates may fall, a tracker may be worth comparing.
Test the payment difference first
Use our UK Mortgage Repayment Calculator to compare monthly payments at different fixed and tracker rate assumptions.
Quick answer: fixed rate or tracker?
Choose a fixed rate if payment certainty matters most. Choose a tracker only if you can handle payment changes and understand that the rate can rise as well as fall.
| Feature | Fixed-rate mortgage | Tracker mortgage |
|---|---|---|
| Monthly payment | Stays the same during the fixed period | Can rise or fall when the tracked rate changes |
| Main benefit | Budget certainty | Potential benefit if rates fall |
| Main risk | You may miss out if rates fall | Your payment may rise if rates increase |
| Best suited to | Borrowers who value stability | Borrowers with spare monthly capacity and higher risk tolerance |
| Common watch-out | Early repayment charges and product fees | Rate rises, collars, margins and exit terms |
How a fixed-rate mortgage works
A fixed-rate mortgage locks your interest rate for a set period, commonly two, three, five or ten years. During that fixed period, your monthly mortgage payment is protected from interest-rate rises.
This makes budgeting easier. If your mortgage payment is one of your biggest household costs, knowing it will stay the same can be valuable.
- Good for certainty: your payment does not change during the fixed period.
- Good for tight budgets: you are protected from rate rises during the deal.
- Less flexible: early repayment charges can apply if you leave early or overpay too much.
- Possible downside: if rates fall, you may stay locked into a higher rate.
Fixed-rate fit: fixed deals are often attractive when you want payment stability more than the chance of benefiting from future rate falls.
How a tracker mortgage works
A tracker mortgage usually follows a reference rate plus a set margin. Many UK tracker products follow the Bank of England Bank Rate, although you should always check the product terms.
For example, a tracker might be Bank Rate plus 0.75 percentage points. If Bank Rate were 3.75%, the mortgage rate would be 4.50%. If Bank Rate moved to 4.25%, the mortgage rate would rise to 5.00%. If Bank Rate moved to 3.25%, the mortgage rate would fall to 4.00%.
- Good for flexibility: some trackers have lower or no early repayment charges, depending on the product.
- Possible lower starting rate: trackers can sometimes look cheaper than fixed deals.
- Rate movement risk: your payment can increase if the tracked rate rises.
- Terms matter: some trackers may include collars, minimum rates, fees or restrictions.
Tracker reality: a tracker is not a one-way bet on rates falling. It can become more expensive quickly if the tracked rate rises.
Example: what happens when rates move?
The easiest way to compare fixed and tracker mortgages is to test different rate scenarios on the same mortgage balance.
| Scenario | Mortgage rate tested | Estimated monthly payment on £250,000 over 25 years | What it shows |
|---|---|---|---|
| Lower-rate scenario | 4.00% | About £1,320 | Payment falls if the rate available to you falls |
| Middle scenario | 5.00% | About £1,461 | Useful baseline for comparison |
| Higher-rate scenario | 6.00% | About £1,611 | Payment rises if rates move against you |
The difference between 4% and 6% is roughly £291 a month on this example. That is why a tracker should be judged by the payment you could afford after a rise, not just the starting payment.
Stress-test your own mortgage payment
Change the interest rate in the repayment calculator to see how much a 1% or 2% rate move would affect your monthly payment.
Fees, lock-ins and early repayment charges
The headline interest rate is only one part of the decision. Arrangement fees, valuation fees, broker fees and early repayment charges can change which deal is cheaper overall.
Fixed-rate mortgages often come with early repayment charges during the fixed period. Trackers can sometimes be more flexible, but this is not guaranteed. Some tracker deals still have fees, tie-ins or exit conditions.
- What is the product or arrangement fee?
- Does the deal have an early repayment charge?
- Can you overpay without a penalty?
- Can you move home and port the mortgage?
- What standard variable rate will you move onto after the deal ends?
Compare fee break-even before switching
Use our Remortgage Comparison Calculator to see whether a lower rate saves enough to justify a product fee.
When a fixed rate may suit you better
A fixed rate may be the better fit when certainty is worth paying for. That does not mean the rate will always be the cheapest in hindsight; it means you are paying for stability.
- Your budget would be stretched if payments rose.
- You prefer knowing the exact mortgage payment each month.
- You have young children, childcare costs or other fixed household commitments.
- You are a first-time buyer and want fewer moving parts.
- You think rates could rise or stay high during the next few years.
- You value certainty more than the chance of benefiting from rate cuts.
Simple test: if a £150–£300 monthly increase would cause stress, a fixed rate may be more suitable than a tracker even if the tracker starts cheaper.
When a tracker may suit you better
A tracker may suit you if you can handle rate movement and want the possibility of benefiting if rates fall. It may also appeal if the product has fewer restrictions or lower exit costs than a fixed deal.
- You have spare monthly income and can absorb payment rises.
- You believe rates may fall and are comfortable being wrong.
- You want more flexibility than a fixed-rate lock-in may allow.
- You may move or remortgage soon and want to avoid heavy exit charges.
- You understand the margin, collar, fees and exit terms.
Tracker test: before choosing one, calculate the payment if your rate were 1% or 2% higher. If that payment would be uncomfortable, the tracker may be too risky.
Two-year fixed, five-year fixed or tracker?
The fixed-versus-tracker decision often overlaps with the length of the deal. A two-year fixed gives shorter certainty and another remortgage decision sooner. A five-year fixed gives longer certainty over the mortgage term but could feel expensive if rates fall.
A tracker sits differently. It may give more rate movement and sometimes more flexibility, but you carry the risk that payments rise during the period.
| Option | Best if | Main drawback |
|---|---|---|
| Two-year fixed | You want short-term certainty and flexibility to reassess sooner | You may face remortgage fees and rate uncertainty sooner |
| Five-year fixed | You want longer payment certainty | You may be locked in if rates fall or your circumstances change |
| Tracker | You can handle payment changes and want rate movement exposure | Your payment can rise if the tracked rate rises |
A practical decision framework
The right choice should come from your budget first, not from a guess about the next Bank Rate decision.
- Calculate your payment at the fixed rate available to you.
- Calculate your payment at the tracker rate today.
- Stress-test the tracker payment at 1% and 2% higher.
- Add product fees and early repayment charges to the comparison.
- Check whether you might move, overpay or remortgage before the deal ends.
- Decide whether certainty or flexibility matters more for your household.
Best answer: choose the option that is still affordable if your prediction is wrong.
Common mistakes to avoid
The biggest mistake is choosing the lowest starting payment without checking what happens next.
- Ignoring payment shock: tracker payments can rise when the tracked rate rises.
- Comparing rate only: fees and early repayment charges can change the true cost.
- Assuming rates will fall: rate forecasts can be wrong.
- Fixing for too long without flexibility: life plans can change before the fixed term ends.
- Forgetting the follow-on rate: check what happens when the deal period finishes.
- Not stress-testing affordability: calculate the payment at higher rates before choosing a tracker.
Fixed rate vs tracker mortgage FAQs
Is a fixed-rate or tracker mortgage better?
Neither is automatically better. A fixed rate gives payment certainty. A tracker can benefit if the tracked rate falls, but your payment can also rise if the tracked rate increases.
What is the main risk of a tracker mortgage?
The main risk is that the tracked rate rises and your monthly mortgage payment increases. You need enough spare budget to absorb that risk.
What is the main risk of a fixed-rate mortgage?
The main risk is that rates fall after you fix, but your payment stays locked at the agreed rate. Fixed deals can also have early repayment charges if you leave early.
Does a tracker mortgage follow the Bank of England Bank Rate?
Many trackers follow the Bank of England Bank Rate plus a set margin, but not all products are identical. Check the product terms for the tracked rate, margin, collar, fees and exit rules.
Should I fix my mortgage if rates might rise?
A fixed rate may suit you if payment certainty is more important than trying to benefit from future rate falls. It can protect you from rises during the fixed period, but it may cost more if rates fall.
Compare the full mortgage cost
Before choosing fixed or tracker, compare the monthly payment, product fee, break-even point and how much risk your budget can handle.
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Related mortgage tools and guides
Sources used for factual context: Bank of England Bank Rate page, MoneyHelper guidance on mortgage interest-rate options, and FCA support guidance for borrowers affected by higher mortgage costs. Check current rates, lender terms and product fees before future publication updates.