Spain's mortgage benchmark has risen for a third straight month. The September average reached 3.247%, putting more pressure on variable-rate borrowers at their next review.
The 12-month Euribor daily rate reached 3.379% on September 25. That was its highest daily level since July 2024. The monthly average later settled at 3.247%, according to the figures cited in the report.
August's average was 2.954%. The September figure is also the highest monthly level since July 2024 and extends the rise to a third consecutive month. The Banco de España still has to confirm the monthly average, but borrowers with variable-rate loans are already facing higher instalments at their next review.
The gap is clear.
On 10 September 2026, the European Central Bank raised all three key interest rates by 25 basis points: the deposit facility rate to 2.50%, the main refinancing rate to 2.65% and the marginal lending facility rate to 2.90%.
The annual comparison is worse for borrowers.
In September 2025, the Euribor stood at 2.172%. On a €150,000 mortgage over 25 years with an interest rate set at Euribor plus 1%, yearly repayments will rise by more than €1,000. For a €300,000 loan under the same terms, the extra annual cost could reach €2,100.
EFE reported that the benchmark also moved above 3% on a daily basis in August. That had not happened since September 2024. September continued the rise seen in August instead of reversing it.
The September average is substantially above the 2.172% recorded a year earlier. For variable-rate borrowers, the relevant effect will appear when their mortgage is next reviewed, while existing fixed-rate loans are not directly affected by Euribor until their fixed period ends.
The European Central Bank's decision on September 10 was the immediate trigger cited in the report. The ECB raised rates by 25 basis points, its second increase of the year. In its official communication, the bank linked the decision to its aim of bringing inflation back to its 2% medium-term target.
Kelisto analysts say the Euribor rise is not only a reaction to that decision. Markets have also raised their expectations for how high rates may go and how long they may stay high while inflation remains under control. The ECB's three key rates are now 2.50% for the deposit facility, 2.65% for main refinancing operations and 2.90% for the marginal lending facility.
Spain's inflation rate has added to that pressure. The consumer price index rose to 4.9% in September, according to Spain's National Statistics Institute, INE, and the same analysis. Kelisto also points to higher bond yields as investors reassess the likely path of interest rates. Energy risks have added to expectations that borrowing costs may stay high for longer.
The year-end forecast depends heavily on inflation and energy prices. Kelisto expects the Euribor to finish the year between 3.1% and 3.3% if energy prices ease. If inflation remains higher than expected and the ECB raises rates again, the estimate rises to 3.4%.
HelpMyCash mortgage analyst Miquel Riera links the September increase to the return of inflation and the possibility of another ECB move. He also says the conflict in the Middle East could affect the benchmark in the coming months. HelpMyCash gives a lower estimate near 2.8% if tensions ease. Its higher scenario puts the rate around 3.5% or above if inflationary pressure continues and rates rise again.
The pressure is spreading.
The Euribor now sits 1.075 percentage points above its level a year earlier. That difference can add more than €1,000 to annual payments on a €150,000 mortgage. The increase reaches €2,100 a year on a €300,000 loan. Existing fixed-rate borrowers do not face a direct Euribor adjustment until their fixed period ends. New mortgages and refinancing are already becoming more expensive.
This is more than a one-month change. Three consecutive increases and a September average of 3.247% point to a wider shift in expectations for inflation and interest rates. Unless price pressures ease or the ECB changes course, households with variable-rate loans will carry most of the burden.
