Iran does not set your mortgage rate. UK lenders do. But many landlords still judge a fixed rate by what happened to rates after they chose it.

You take a 5-year fix. Rates fall later. You feel you lost.

You take a 2-year fix. Rates rise later. You feel you lost.

That is the wrong test.

A fixed rate should fit your plan. It should protect your cashflow. It should leave enough margin after mortgage interest, fees, voids, repairs, tax and insurance.

Your goal is not to beat the market. Your goal is to make a clear cost decision with the facts you have today.

The 2026 Mortgage Backdrop

The Bank of England held Bank Rate at 3.75% on 18 June 2026. CPI inflation was 2.8%, above the 2% target. The Bank also flagged that energy costs remain a risk following disruption in the Middle East.

UK Finance expects 1.8 million fixed-rate mortgages to end in 2026. It also expects external remortgaging to rise by 10% and product transfers to rise by 2%.

This matters because many borrowers will make a new rate choice this year — and many landlords will be comparing 2-year against 5-year fixed rates.

Fixed rates can move before Bank Rate changes. Lenders price fixed rates around funding costs and interest-rate expectations. Swap rates have a direct effect on many fixed-rate mortgage products.

How Much Do Rates Need to Fall After 2 Years?

A 2-year fix can look attractive if you think rates will fall. But if the 2-year fix costs more than the 5-year fix today, you pay extra from day one.

The real question is: how much do rates need to fall after 2 years for the shorter fix to break even against the cheaper 5-year option?

The LHS Rate Switch tool is built for exactly this purpose. It helps you compare a more expensive 2-year fixed rate with a cheaper 5-year fixed rate, and shows how far rates need to fall later for the shorter fix to make financial sense.

This is the right framing for buy-to-let investors. The question is not whether you will win or lose. It is whether the extra cost today gives you a realistic chance of a lower cost later.

A Simple Buy-to-Let Example

Here is a straightforward interest-only example. Buy-to-let mortgage balance: £200,000

Rate
Option A	5-year fix	4.90%
Option B	2-year fix	5.60%

Rate gap: 0.70 percentage points
Extra interest on the 2-year fix: £1,400 per year
Extra interest over 2 years: £2,800

Now add a £1,995 product fee for the next deal when the 2-year fix ends. Total extra cost: £4,795 — before any valuation, legal, broker or administration costs.

To recover £4,795 over the remaining 3 years on a £200,000 interest-only loan, the future rate would need to be about 0.80 percentage points lower than the 5-year fixed rate. In this example, a 4.90% 5-year fix would need to be compared with a future rate near 4.10% after fees are allowed for.

That does not mean the 2-year fix is wrong. It means the shorter fix needs a clear reason.

Your figures will change with loan size, fees, tax position, repayment type, rent cover and lender terms. Use your own numbers before you decide.

When the 5-Year Fix Can Be the Better Choice

A longer fixed rate can help a buy-to-let investor when certainty has value. A 5-year fix may suit you if:

You want known payments for longer
Your cashflow has little spare margin
You hold the property for income, not a short sale
You have several properties and want fewer refinance dates
You need to plan repairs, EPC work or service charge rises
You do not want to rely on a rate fall within 2 years
The 5-year rate is cheaper than the 2-year rate today

Buy-to-let lending can be stricter than residential lending. Lenders often test rent against interest costs. A lower fixed rate can help your rental cover. A longer term can also give you more time before the next lender review.

When a 2-Year Fix Can Still Make Sense

A 2-year fix can still be the right choice. You need a reason that fits your plan. A shorter fix may suit you if:

You plan to sell the property within 2 years
You plan to refurbish, raise the rent and refinance
You expect your loan-to-value to improve soon
The gap between the 2-year and 5-year rates is small
You have cash reserves if rates do not fall
You want flexibility and accept the extra cost

The mistake is not choosing a 2-year fix. The mistake is choosing it because you hope rates fall, without first checking the break-even point.

Use the Rate Switch Tool Before You Choose

Open the LHS Rate Switch tool before you choose between a 2-year and 5-year fixed rate. Use it to test:

Your mortgage balance
The 2-year fixed rate
The 5-year fixed rate
Product fees
Monthly payment difference
Extra cost during the first 2 years
The future rate needed after 2 years to break even

If the tool shows that rates need to fall by 0.75% or more, ask yourself whether you are comfortable paying extra today for that outcome. Also ask whether your rent cover still works if rates do not fall.

Also Use the Remortgage Savings Calculator

The Rate Switch tool is designed specifically for comparing 2-year versus 5-year fixed-rate options.

For comparing your current mortgage with a new deal, use the LHS Remortgage Savings Calculator instead. It includes fees, early repayment charges and break-even analysis. Use it to find out:

Whether a refinance could save you money
How much your monthly payment may change
How long it takes to recover fees and charges
Whether switching now is worth the cost
How total savings look over the fixed-rate period

Check the Whole Cost, Not Only the Rate

A lower rate can still cost more if the fee is high. A higher rate can still fit if it gives you the term and flexibility you need.

Before you choose a product, check:

The interest rate
The product fee
Valuation and legal costs
Broker and administration fees
Early repayment charges
Rental cover and lender stress tests
Void periods, repairs and insurance
Tax treatment
Exit plans

Since 1 May 2026, rent increases under the Renters Rights Act require more care. Landlords must follow the correct route, and tenants can challenge rises above open-market rent. That makes cashflow planning more important than ever.

A Practical Way to Decide

1. Start with your holding period. Decide how long you expect to keep the property. 2. Compare the 2-year and 5-year rates using the LHS Rate Switch tool. 3. Add fees, not only the monthly payment. 4. Look at the rate fall needed after 2 years. 5. Check whether your rent still covers the mortgage if rates stay where they are. 6. Use the LHS Remortgage Savings Calculator if you are comparing your current mortgage with a new refinance deal.

Choose the product that fits your cashflow, risk and plan.

The Key Point

Do not call a fixed rate a win or a loss because rates moved after you chose it.

A 5-year fix can still be the right decision if it gives you a lower rate today, fewer refinance costs and more payment certainty.

A 2-year fix can still be the right decision if you have a clear plan and the break-even rate is realistic.

Use the LHS Rate Switch tool to test the 2-year versus 5-year break-even point. Use the LHS Calculators section to test standard remortgage savings. That gives you a clearer decision than guessing where rates will be in 2 years.

*Important notice: This article is for general information only. It is not mortgage, tax, legal or investment advice. Mortgage availability depends on your circumstances, property type, rental income and lender criteria. Most buy-to-let mortgages are not regulated by the Financial Conduct Authority, although this depends on the case. Your property may be repossessed if you do not keep up repayments on a mortgage secured on it.* Sources

LHS Worldwide, Rate Switch tool
LHS Worldwide, Calculators
Bank of England, Interest rates and Bank Rate, latest decision
Office for National Statistics, Consumer price inflation, UK, May 2026
UK Finance, Mortgage Market Forecasts
Moneyfacts Compare, Buy-to-let mortgage rates
IMLA, How lenders fund fixed-rate mortgages (swap rates explained)
GOV.UK, Renters Rights Act overview for landlords

Fixed Rates and Buy-to-Let: Why a 2-Year Fix Is Not Always a Win