The Iran war and the Euribor. Should you worry if you have a variable-rate mortgage?

Every time a crisis erupts in the Middle East, the same question reaches anyone with a variable-rate mortgage: is the Euribor going to go up? The Iran war of June 2025 — twelve days of strikes between Israel and Iran, with US intervention against the nuclear facilities at Fordow, Natanz and Isfahan — was an almost perfect case study of how a geopolitical shock is transmitted (or not) all the way to your monthly mortgage payment.

The transmission chain: from missile to your monthly payment

The Euribor doesn’t react to headlines, but to expectations about the European Central Bank’s interest rates. For a war in the Middle East to move your payment, it has to travel down this entire chain:

1. Oil. Iran controls the Strait of Hormuz, through which roughly a fifth of the world’s crude oil passes. A conflict that threatens that flow sends the price per barrel soaring.
2. Inflation. If oil stays expensive for months, it drives up the cost of transport, energy and, with a lag, almost the entire European shopping basket.
3. The ECB. With inflation rebounding, the ECB becomes more reluctant to cut its official rates, or even raises them if the shock is persistent.
4. The Euribor. Banks, which lend money to each other in anticipation of what the ECB will do, pass those expectations on to the 12-month Euribor, the index most variable-rate mortgages in Spain are referenced to.

The key word is persistence. A two-week scare barely reaches the third link in the chain; a conflict that closed Hormuz for months would.

What actually happened in June 2025

The 2025 episode illustrates it well:

• Brent crude rose around 10% in the first days of the conflict, climbing above 75 dollars, with peaks above 78.
• The market was pricing in far worse scenarios (a closure of Hormuz, attacks on Gulf oil infrastructure) that never materialised.
• With the ceasefire in late June 2025, crude gave back almost the entire rise within a matter of days.
• The 12-month Euribor, which had been falling from its 2023-2024 highs, barely flinched: it kept trading at around 2% throughout the entire episode. The ECB, which had just cut rates that very month, did not change its roadmap.

In other words: the largest direct military confrontation between Israel and Iran in recent history moved oil by 10% for two weeks, and the effect on the Euribor was, in practice, indistinguishable from zero.

So why has the Euribor risen since then?

By mid-2026 the 12-month Euribor is hovering around 2.8%, clearly above the 2025 lows (the 2025 annual average came in at around 2.2%). But attributing that rise to the war would be confusing correlation with cause. The main drivers have been elsewhere:

• The end of the ECB’s rate-cutting cycle, once eurozone inflation stabilised near its 2% target.
• Expectations of higher European public spending (defence and infrastructure), which put upward pressure on long-term rates.
• A European economy that has held up better than expected, reducing the urgency for further stimulus.

Geopolitics contributes to the background noise — an energy risk premium that appears and disappears — but the level of the Euribor is set by monetary policy.

What to do if you have (or are about to sign) a mortgage

• If you have a variable-rate mortgage: your reference point is your review date. What matters is not a single day’s peak, but the monthly average of the Euribor in the month of your review. You can see the official historical series on our homepage and simulate scenarios with the mortgage calculator, which includes an analysis using the index’s historical minimum and maximum.
• If you’re about to sign: compare the real cost of fixed, mixed and variable rates with each bank’s current rates in our mortgage comparison. A short war is no reason to change strategy; your risk profile and the spread you’re offered are.
• In general: be wary of headlines announcing imminent Euribor rises every time there is tension in the Middle East. The historical series shows that the index responds to the ECB, not to missiles.

Sources, always

The Euribor figures cited come from the official series of the European Central Bank; the index is administered by the European Money Markets Institute (EMMI) and can also be consulted at the Banco de España (the Bank of Spain). The crude oil prices correspond to Brent during the days of the conflict (June 2025).