Spain Diesel Tax Cut: 20 Cents Per Litre from September 2026
Spain's diesel tax reduction rises to 20 cents per litre in September after diesel inflation passed the legal 15% trigger. Petrol stays at 5 cents.
Drivers of diesel vehicles in Spain will receive a larger fuel-tax reduction from 1 September 2026. The reduction rises to 20 cents per litre, rather than falling to the 5 cents originally scheduled for September.
The change is automatic under Real Decreto-ley 18/2026: July's diesel CPI rose 15.7% year on year, above the law's “more than 15%” trigger.
Why is diesel getting a bigger reduction?
Spain introduced a staged return towards normal fuel-tax rates as part of its response to higher energy costs linked to the crisis in the Middle East. The timetable provided reductions of 15 cents per litre in July, 10 cents in August and 5 cents in September for widely used road fuels.
The decree also set separate safeguard tests for petrol and diesel. If the July 2026 CPI for either fuel was more than 15% above July 2025, that fuel's September excise-duty reduction would rise to 20 cents per litre.
Final figures published by Spain's National Statistics Institute (INE) show diesel up 15.7% year on year. That activates the higher diesel rate automatically.
Petrol remains at 5 cents per litre
Petrol rose by approximately 7.3% over the same period, well below the legal threshold. Its September reduction therefore remains 5 cents per litre.
| Fuel | September tax reduction |
|---|---|
| Diesel | €0.20/litre |
| Petrol | €0.05/litre |
What does the diesel reduction mean in practice?
Measured against the normal excise-duty rate, the reduction is worth €10 on 50 litres of diesel and €12 on 60 litres. These are simple tax comparisons, not a promise that the displayed pump price will fall by exactly those amounts from one day to the next.
This is a reduction in the Impuesto sobre Hidrocarburos, not a separate cash payment. Wholesale costs, station margins and VAT still affect the price displayed at the pump.
Why have fuel prices increased?
Energy costs have again become a major contributor to Spanish inflation. INE confirmed that the overall annual CPI rate increased to 3.6% in July, from 3.2% in June. Transport inflation rose particularly strongly as fuels and lubricants became more expensive.
Diesel experienced the sharper annual rise. The higher tax support provides some relief, but it has been triggered precisely because diesel prices increased so quickly.
When does the 20-cent diesel reduction apply?
The higher rate applies from 1 September until 30 September 2026. The current decree does not extend it beyond that month. Any October support would need a new or amended government measure.
Do drivers need to apply?
No. Ordinary motorists do not need to register, keep receipts or submit a reimbursement claim. The measure operates through the tax rate included in fuel pricing, and the decree requires the reduction to be passed on to consumers.
A useful saving, but diesel remains expensive
The move from the planned 5-cent reduction to 20 cents will soften September fuel costs for diesel drivers. It does not mean every station will display the same price or that diesel must be exactly 20 cents cheaper than it is today.
Compare live fuel prices near you before your next fill.
Sources
Checked 15 August 2026. Tax figures refer to the reduction in the excise-duty rate set by the decree.