· Verified on 7 September 2026
The September phase of the measures concerning Spain's Hydrocarbon Tax has applied since 1 September 2026. Its legal basis is Royal Decree-law 18/2026, approved on 29 June and published the following day. The development this month is the implementation of the schedule and its conditions, not the approval of a new general reduction for all fuels.
The September notice issued by the Spanish Tax Agency compares rates with those in force up to 21 March 2026. It shows a reduction of 20 euro cents per litre for diesel and 5 euro cents for 95- and 98-octane petrol. It also lists category B diesel separately: the figure announced for road diesel should not automatically be applied to it.
The legislation includes conditions linked to year-on-year price changes for each fuel. A news report simply stating that fuel taxes are falling therefore leaves out a crucial distinction between products. On 1 September, Cadena SER explained that the month's change favoured diesel while tax support for petrol was reduced compared with August.
The size of a tax reduction and the savings on an invoice answer different questions. The former compares a tax component with a specific reference; the latter requires the full commercial price of two comparable deliveries. This article does not claim that the final price will fall by exactly 20 euro cents compared with August, nor does it announce a new VAT reduction.
For a diesel or heating oil order, first identify the product and its use: road transport, agriculture or heating. Then compare volume, destination, date, taxes included and delivery terms. A headline about road diesel should not be applied to every use of these fuels, nor should different forms of support be added together without checking who is eligible.
The information is verified as of 6 September and describes the period from 1 to 30 September 2026. Before using it for an order in another month, the legislation and rates applicable at that time will need to be reviewed.