Madrid wrote the threshold itself. Royal Decree-Law 25/2026, of 29 September, says VAT on power falls from 21% to 10%, and the special electricity tax from 5.11% to 0.5%, in November, only if September’s electricity CPI is more than 15% above September 2025. INE published, on 14 October, 11.4%. The bar is not met. In November, on ordinary bills, the general rates stay.

El Mundo writes that, on a typical OCU bill of about €86, another three euros would have pushed the index over the line — and households would then have saved roughly eleven euros in November. That is “close” in the paper’s arithmetic, not in the wholesale market’s. On OMIE, the generation price rose from €42.44/MWh in April to €143.25 in September, more than double a year earlier and the highest in four years. Eight million homes on the regulated PVPC tariff, still partly tied to the market, already pay 27.5% more than a year ago.

Why doesn’t the CPI show the same jump? Because INE weighs what all households pay. More than seven in ten are on the free market, most of them on fixed prices that delay the shock. After the PVPC reform in Teresa Ribera’s time, more than half of the regulated tariff is set on the forward markets, which move more slowly. The clause does not look at the pool, nor at headline inflation. It looks at subclass 04.5.1.0, Electricity. That is why five months of rises on the exchange do not unlock the lower VAT.

For motor fuel the formula is reversed. The same anti-crisis package, also framed around the Middle East conflict, already cut hydrocarbon duty: 20 cents a litre in October, 13 in November, 6 in December — snapping back to 20 if CPI clears 15%. Diesel rose 34% in September, petrol 27.5%. So in November the pump discount stays at 20 cents, rather than falling to 13. For power, the cut is not guaranteed at all. The tax agency has it in black and white: November is judged on September; December on October, when INE publishes in November.

If the December bar were met, 10% VAT would not go to everyone. The rule ties it to contracts of 10 kW or less and to holders of the social bonus in severe vulnerability. The special tax cut to 0.5% has no such power cap, but it cannot fall below the EU directive floors. In the Canaries, Ceuta and Melilla the peninsular 21% VAT does not apply; they have other indirect taxes.

OCU put a typical PVPC October bill 23% higher than a year ago; VAT at 10% would have saved about eight euros a month. Anyone on the free market who is renewing already sees steeper offers. December is not buried: an October electricity CPI above 15% would open the door. Until then the clause does exactly what it was written to do. It is not a last-minute slip. It is the rule.

Image: Heparina1985, Real Casa de la Aduana (Finance Ministry), Madrid, 21 January 2020, CC BY-SA 4.0, Wikimedia Commons. The photograph shows the building, not a November bill.

Sources consulted: La cláusula del Gobierno bloquea por la mínima la rebaja del IVA de la luz — El Mundo; Medidas extraordinarias en el Impuesto Especial sobre la Electricidad — Agencia Tributaria; La enrevesada fórmula del Gobierno para no bajar IVA de la luz aunque el recibo se dispare — ABC.