Portugal Reclaims Part of Its Fuel-Tax Discount on Monday, Betting That Pump Prices Will Fall Anyway
A portaria in force from 31 August lifts the ISP on diesel by €9.98 per 1,000 litres and on petrol by €2.36. The government is narrowing the rebate because it expects the underlying price to drop.
Portugal's temporary fuel-tax discount works in both directions, and this week it goes into reverse. A portaria signed on 28 August and published in the Diário da República (Official Gazette) raises the unit rates of the Imposto sobre os Produtos Petrolíferos e Energéticos (Tax on Petroleum and Energy Products, or ISP) from Monday 31 August, clawing back part of the relief drivers have been getting all month.
On road diesel the ISP rate goes from €279.99 to €289.97 per 1,000 litres. On unleaded petrol it goes from €443.54 to €445.90. In pump terms that is almost exactly one cent a litre more tax on diesel and a quarter of a cent on petrol, before value added tax; with VAT at 23 percent applied on top, roughly 1.2 cents and 0.3 cents respectively.
The government is trimming the discount because it expects prices to drop
The discount itself, stated in the portaria's own preamble, falls from €81.61 to €71.63 per 1,000 litres on diesel and from €53.98 to €51.62 on petrol. The reasoning is set out plainly: the government expects a fall in the price of road diesel and unleaded petrol next week, and has therefore decided to adjust the extraordinary and temporary ISP discount downwards.
That is the mechanism operating as designed rather than a policy change. The relief is triggered when the price of either fuel sits more than 10 cents above the reference week of 2 to 6 March, and it is calibrated to hand back the extra VAT the state collects when prices rise. When the underlying price eases, the extra VAT shrinks, and so does the amount there is to give back. Readers who followed last week's widening of the same rebate are watching the identical formula run the other way.
Where this sits against the rest of August
The month has not been a straight line. The rates in force from 10 August carried a discount of €59.16 on diesel and €35.39 on petrol. That widened to €80.52 and €49.61 from 17 August, then to €81.61 and €53.98 from 24 August, which was the deepest diesel relief of the month. Monday's rates unwind about an eighth of that.
Even so, drivers are better off than they were three weeks ago. The ISP on diesel stood at €302.44 per 1,000 litres in the week from 10 August. At €289.97 it is still €12.47 lower, about 1.5 cents a litre before VAT. Petrol has moved less: €462.13 then against €445.90 now.
What actually lands at the pump
The tax change is only one half of the sum. If the price fall the government is anticipating materialises, the net effect on Monday could still be cheaper fuel, with the clawback absorbing part of the drop rather than adding to a rise. If it does not materialise, drivers pay the extra tax without the offsetting relief. That asymmetry is the standing criticism of a weekly discount set on a forecast.
The legal basis is article 92(1) of the Código dos Impostos Especiais de Consumo (Excise Duty Code). The order was signed by the Ministra do Ambiente e Energia (Minister for the Environment and Energy), Maria da Graça Carvalho, and the Secretária de Estado dos Assuntos Fiscais (Secretary of State for Tax Affairs), Cláudia Melo de Carvalho. Both rates include the ring-fenced road service levy: €111 per 1,000 litres on diesel and €87 on petrol.
The energy regulator concluded earlier this month that Portuguese pump prices do not in fact rise faster than they fall, and rejected capping retail margins. Monday will be a small test of the tax side of that claim.
