Treasury implements the corrective self-assessment in the Coal Tax

The Ministry of Finance has approved Order HAC/988/2026, of September 16, which adapts form 595 of the Special Tax on Coal to the new system of rectifying self-assessment. The provision is published in the Official State Gazette (Boletín Oficial del Estado) no. 236, of September 24, 2026, section I, pages 125472 to 125478, with official reference BOE-A-2026-19762. The new form will be applied for the first time to settlement periods beginning on or after January 1, 2027.

The order modifies Order EHA/3947/2006, of December 21, which approves the forms, deadlines, requirements, and conditions for the declaration-settlement and the annual summary declaration of operations for this tax. The change responds to the new wording of Article 120 of the General Tax Law introduced by Law 13/2023, of May 24, and Article 140 bis of the Special Taxes Regulations, added by Royal Decree 117/2024, of January 30.

The text consists of a preamble, a single article with two sections, and a single final provision, and was signed in Madrid on September 16, 2026, by the Minister of Finance, Arcadi España García.

A form 595 with rectification boxes

The regulation replaces Annex I of Order EHA/3947/2006 and incorporates a new group of fields into form 595 called “B. Rectifying self-assessment.” The taxpayer may rectify, complete, or modify a previous self-assessment without waiting for an administrative resolution, by indicating the receipt number of the previous declaration.

The admitted reasons for rectification are three:

• Error in the previous self-assessment or any other cause.
• Discrepancy in interpretive criteria.
• Violation by the applied rule of higher-ranking legal, constitutional, European Union Law, or an International Treaty or Convention.

In the latter case, the taxpayer may choose between the rectifying self-assessment or the traditional rectification request procedure. Self-assessments for periods prior to the first quarter of 2027 may not avail themselves of this system.

New coal activity keys

The order adds an Annex VI with the keys to configure the Coal Activity Code (CAC), in compliance with Article 138.3 of the Special Taxes Regulations. These codes were previously regulated in DAIE NS 1/2019, of January 23, from the Sub-directorate General for the Management and Intervention of Special Taxes.

The approved keys are:

• CE: producers and extractors.
• CC: consumers via intra-community acquisitions.
• CR: resellers.
• IM: importers.
• TR: final consumers with the tax rate of heading 1.1.
• RQ, PM and NC: beneficiaries of exemption for chemical reduction, electrolytic and metallurgical processes, mineralogical processes, and uses that do not involve combustion.

Deadlines, taxable base, and entry into force

The model maintains headings 1.1 (coal for professional uses) and 1.2 (other uses) of article 84.1 of Law 38/1992, of December 28, on Special Taxes. The taxable base is calculated based on the energy content of the coal expressed in gigajoules, and the quota results from applying the rate in force at the time of accrual.

Tax return-settlements must be submitted within the first twenty calendar days following the end of the quarter in which the accruals occur. Submission will not be required when there are no quotas to be paid.

The order enters into force the day following its publication in the Official State Gazette (Boletín Oficial del Estado), that is, September 25, 2026, although its effective application is deferred to the first quarter of 2027.

The change forces energy, extraction, resale, and coal importing companies to review their settlement procedures and correctly identify their activity code before the start of 2027. The unification of the rectification into a single model reduces formalities and eliminates the wait for an administrative resolution, but requires adapting electronic filing systems to the new fields.

Source: Official State Gazette, no. 236, of September 24, 2026, section I, pp. 125472-125478 (official reference: BOE-A-2026-19762).