When interest rates move, one question inevitably comes back for anyone thinking about buying a home: should I choose a fixed-rate or a variable-rate mortgage?
The answer often seems to depend on one thing: where interest rates are going.
When Euribor rises, fixed rates suddenly look attractive. When rates fall, variable mortgages seem like the obvious choice. And when rates are somewhere in between, the decision becomes even harder because nobody knows what will happen next.
But perhaps the problem starts with the question itself.
Choosing between a fixed and a variable mortgage is not really about predicting interest rates. It is about deciding how much interest-rate risk you want to assume yourself, and how much you are willing to pay to transfer that risk to the bank.
The bank already knows a lot about the future
There is a common perception that when a bank offers a fixed-rate mortgage, it is effectively making a bet about where interest rates will go.
It is more complicated than that.
Banks price mortgages using a wide range of information: market interest rates across different maturities, funding costs, credit risk, capital requirements, margins, competition and, importantly, the cost of hedging their own interest-rate exposure.
The interest-rate curve is particularly relevant. It incorporates the information currently reflected in financial markets about future inflation, monetary policy and interest rates, together with risk premia and other factors. It is therefore an important input into the pricing of longer-term fixed-rate financing.
This means that when you compare a fixed mortgage with a variable one, you are not comparing a rate chosen in isolation with another rate that somehow represents “the real market price”.
The bank has already considered the relationship between the two.
That does not mean the bank knows what interest rates will do.
The market can be wrong. Banks can be wrong. Expectations embedded in the yield curve can turn out to be completely different from what actually happens.
But there is an important distinction between saying that the bank can be wrong and assuming that the bank has failed to incorporate the available information when pricing its mortgage.
For an individual borrower, consistently finding an obvious mispricing between fixed and variable rates is therefore a difficult proposition.
The more useful question is not “What does the bank think interest rates will do?”
It is:
“What happens to my finances if interest rates behave differently from what the market currently expects?”
A fixed mortgage buys certainty
The easiest way to understand the difference is to think about what you are actually buying.
With a fixed-rate mortgage, you are buying predictability.
You accept a known interest rate in exchange for knowing that future changes in Euribor will not affect your mortgage payment in the same way they would with a variable loan. If rates rise significantly, you are protected. If they fall, you will not benefit from that decline.
With a variable mortgage, the situation is reversed. Your rate can move with the reference rate, normally Euribor. If rates fall, your mortgage becomes cheaper. If rates rise, it becomes more expensive.
Neither option eliminates interest-rate risk.
It simply determines who carries it.
This is why a fixed mortgage should not necessarily be viewed as a prediction that rates will rise. It can simply be a decision to eliminate uncertainty from your household finances.
You are effectively saying:
“I don’t know where rates will be in ten years, and I don’t want my financial plan to depend on finding out.”
Your financial situation changes the answer
This is where the decision becomes much more personal.
Imagine two households taking exactly the same mortgage.
The first has stable income, substantial savings and relatively few other financial commitments. If its mortgage payment increased by €300 per month, it would be uncomfortable, but manageable.
The second has limited savings, less predictable income and several other financial commitments. The same €300 increase could force it to reduce saving, postpone other objectives or consume much of its financial buffer.
The mortgage is identical.
The risk is not.
This is why comparing only the initial interest rate can be misleading. What matters is how a change in the mortgage payment interacts with the rest of your financial position.
Your income stability matters. Your savings matter. Your existing debt matters. Your expected expenses matter. Your plans for the next few years matter.
Someone planning to start a business may value certainty differently from someone with a highly stable salary. Someone approaching retirement may have very different priorities from someone at the beginning of their career.
There is no reason for all of these households to make the same mortgage decision.
The longer the mortgage, the harder the forecast
Time is another important part of the equation.
Forecasting interest rates over the next twelve months is already difficult. Forecasting them over twenty or twenty-five years is something else entirely.
Economic growth can change. Inflation can surprise us. Central banks can change their policies. New financial crises can appear. Governments can alter fiscal policy. Structural changes in productivity, demographics or technology can transform the economic environment.
This is why long-term interest-rate forecasts deserve caution.
And paradoxically, the longer the mortgage, the less useful it becomes to base the decision entirely on a forecast.
Instead, the question should increasingly become one of financial resilience.
If rates rise, can you still comfortably afford the mortgage?
If rates remain high for several years, can you continue saving and investing?
If rates fall, how much would you actually benefit from having chosen the variable option?
You do not need to know which scenario will happen.
You need to understand what each scenario would mean for you.
Build the decision around scenarios
This is probably the most useful exercise a borrower can perform.
Take the actual fixed and variable mortgage offers available to you and model the monthly payments under different interest-rate assumptions.
Don’t stop at today’s variable rate. Look at what happens if rates are 1 percentage point higher, or 2 percentage points higher. Then look at the opposite scenario and estimate what happens if rates decline.
The purpose is not to produce a forecast.
It is to understand the range of outcomes your financial position can absorb.
Don’t just ask whether you can pay the mortgage. Ask whether you can continue living the financial life you want while paying it.
Can you continue saving?
Can you invest?
Can you deal with an unexpected expense?
Can you still afford the other objectives that matter to you?
That is a much more meaningful definition of affordability.
So, fixed or variable?
There is no universal answer.
A fixed mortgage may make more sense for someone who places a high value on predictable payments and has limited capacity or willingness to absorb interest-rate volatility.
A variable mortgage may be suitable for someone with greater financial flexibility, sufficient liquidity and the capacity to tolerate changes in monthly payments.
The key point is that neither decision requires you to have a superior forecast of interest rates.
In fact, trying to forecast rates may distract from the information that you actually have.
You know your own balance sheet.
You know how stable your income is, how much liquidity you have, what other commitments you expect to take on and how much uncertainty your finances can absorb.
The bank has better information about the market.
You have better information about yourself.
That is where your advantage lies.
Ultimately, choosing a mortgage is not about predicting whether Euribor will be higher or lower five years from now. It is about deciding how much uncertainty you are comfortable carrying and what that uncertainty means for the rest of your financial plan.
A fixed mortgage charges you for certainty.
A variable mortgage gives you more exposure to the market.
You cannot eliminate interest-rate risk. You can decide who assumes it — and how much you are willing to pay for certainty.
