Fixed vs Tracker Mortgage: Which is Best for Landlords in 2025?

Mortgage rates in 2025 are more complex than in recent years, leaving landlords with an important decision: stick with the security of a fixed rate or opt for the flexibility of a tracker. With interest rates still shaped by wider economic uncertainty, the choice you make can directly affect your cashflow, portfolio strategy and overall financial stability.

There’s no single solution that works for everyone, but understanding how each option works, the risks involved and the situations where one may be more beneficial than the other will help landlords make a more confident and informed decision.

What are Fixed Rate Buy-to-Let Mortgages?

A fixed-rate Buy-to-Let mortgage is a type of mortgage where the interest rate and, therefore, your monthly repayments remain the same for a set period, typically two, three or five years. Unlike other mortgages that can fluctuate in value when interest rates change, a fixed-rate deal provides certainty and consistency.

The biggest advantage of this type of mortgage is protection from rising interest rates. Even if the Bank of England increases rates during your fixed term, your repayments won’t move an inch. This makes it much easier to budget and plan ahead. It can also work in your favour when applying for a mortgage. With 5-year (or longer) fixed deals, some lenders assess affordability based on the actual fixed rate, rather than applying a higher “stress test” rate. This can make it easier to borrow compared to shorter fixes.

Of course, there’s a trade-off. If interest rates fall, you won’t benefit from lower monthly repayments because you’re locked into your fixed rate. But for many landlords, the stability and predictability outweigh that downside.

How Do Tracker Buy-to-Let Mortgages Work?

A tracker mortgage is a type of loan where your interest rate “tracks” the Bank of England’s base rate, plus a set margin decided by the lender. This means your monthly repayments go up or down whenever the base rate changes.

If interest rates fall, you’ll benefit straight away with lower payments. But if rates rise, your costs increase too, making this option less predictable and sometimes harder to budget for.

One advantage of tracker mortgages is flexibility. Many come with little or no early repayment charges, allowing you to refinance or sell the property without incurring significant penalties. This makes them particularly attractive for landlords who plan to hold a property only for a short time, or who expect to restructure their portfolio soon. In these cases, the flexibility can be more valuable than the payment stability of a fixed-rate deal.

Fixed vs Tracker Mortgage: Structures & Costs Compared

Worked Examples in Practice

Let’s look at how fixed and tracker Buy-to-Let mortgages can affect a landlord’s finances using a simple example.

Suppose you have a £200,000 property with a £150,000 interest-only mortgage and receive £1,150 per month in rent.

If you lock in a five-year fixed rate at 5.25%, your monthly repayments stay the same at just over £656 throughout the term. This kind of stability makes budgeting straightforward and can help landlords meet lender affordability requirements, particularly for longer-term fixes.

Meanwhile, a tracker mortgage moves in line with the Bank of England base rate plus a lender's margin. For example, if your tracker is base rate + 1.25%:

• With a base rate of 4.75%, your monthly repayment would be around £750
• If the base rate falls to 4.25%, repayments drop to about £688
• However, if rates rise, monthly payments increase accordingly

Tracker mortgages offer flexibility, often with little or no early repayment penalties, allowing landlords to refinance, sell or make overpayments without extra costs.

When a Fixed Rate is the Right Choice

Fixed rates are ideal for landlords who prioritise stable cashflow. They are particularly useful:

• When rental income is low or properties are undergoing refurbishment
• During periods of tenant turnover
• When a longer fix is required to pass lender affordability checks for other portfolio properties

The main advantage is certainty. Even if interest rates rise sharply, your repayments stay the same, helping with planning and reducing financial stress.

When a Tracker Can Work Better

Tracker mortgages can suit landlords who:

• Expect interest rates to fall
• Plan to sell or refinance in the short to medium term

Their flexibility—absence of punitive early repayment fees and adaptable overpayment terms—allows landlords to exit or restructure a property quickly if needed. For some investors, this flexibility outweighs the potential risk of fluctuating repayments.

Lessons from Case Studies

Consider two landlords:

• A landlord with low-yield flats chose a five-year fixed rate to secure stable repayments and meet lender affordability tests
• Another landlord, planning to sell within a year, opted for a penalty-free tracker, allowing overpayments and a smooth exit without extra charges

These examples show that there is no one-size-fits-all solution. The best choice depends on your financial goals, property type and investment strategy.

Key Considerations for Landlords

Before they reach a conclusion, landlords need to accurately model fixed and tracker cases for all the properties in their portfolio. Variables such as early repayment charges, lender affordability tactics and gross cost after fees all may have a bearing on identifying the most valuable product. Likewise, looking ahead to portfolio transactions such as sales, refurbishments or incorporations can prevent expensive mistakes.

Finally, the choice between tracker and fixed mortgages is a balance between certainty and flexibility. Landlords who need stability in order to preserve cashflow may choose that fixed rates are the more secure option, but others who prioritise agility may think that a tracker is worth it even with the danger of differential payments.

Conclusion

The mortgage market in 2025 is both an opportunity and a threat for landlords. Fixed rates are safer and provide improved protection against affordability, whereas trackers provide flexibility and potential savings should interest rates fall.

Instead of depending on a single strategy across a portfolio, landlords need to approach each property independently, weighing up cashflow robustness, refinancing plans, and overriding investment goals. In doing so, they are able to choose the product that not only suits today's climate but also places them in a position to navigate whatever market turmoil is around the corner.