Spanish Inheritance Tax: How the ISD Works and Why the Region Decides the Bill (2026)

Spain's inheritance tax produces a result that surprises almost everyone: the national law sets a scale that climbs to 34 percent, and yet a spouse or child inheriting in Madrid or Sevilla pays close to nothing, while the same family in another comunidad pays real money. Both things are true, because the state law is only the skeleton and the comunidades put the flesh on it. This page explains the machine, the deadline, and where the regional differences come from.

Information last verified on 23 July 2026. This page provides general legal information about Spanish tax law and does not constitute legal advice in an individual case. Every figure should be checked against the BOE and the comunidad's own rules before acting; each comunidad can change its bonificaciones in any budget cycle.

The deadline comes first

The tax accrues (devengo) on the day of death (art. 24 Ley 29/1987), and the return must be filed within six months of it (art. 67 del Reglamento, RD 1629/1991). One extension exists: six more months, requested by the heirs within the first five months of the original period. If the administration stays silent for a month, the extension is granted, but it is not free: interest runs on the extended period (art. 68). File nothing and the administration can eventually assess the tax itself from the data it holds, with penalties on top.

One planning detail worth knowing early: the value you declare here is also the value later used in the comparison for the municipal plusvalía when real estate is inherited.

The state machine: base, reductions, scale, coefficient

Where a comunidad has not written its own rules, the state defaults apply. The calculation runs in four moves.

1. Base imponible. Each heir is taxed on the net value of his or her share, including life-insurance amounts that accumulate to it.

2. Reductions by kinship group (art. 20 Ley 29/1987):

On top of the group reduction: 47.858,59 € for heirs with a recognised disability of 33 to 65 percent (150.253,03 € at 65 percent or more), and a 95 percent reduction on the deceased's vivienda habitual (capped at 122.606,47 € per heir) for the spouse, ascendants, descendants, or an over-65 collateral who lived with the deceased, conditional on keeping the acquisition for ten years under the state rule.

3. The scale (art. 21): sixteen brackets from 7,65 percent on the first 7.993,46 € up to 34 percent above 797.555,08 €.

4. The multiplier (art. 22): the resulting cuota is multiplied by a coefficient between 1,0 and 2,4 that rises with the heir's pre-existing wealth and with distance of kinship. A wealthy, unrelated heir literally pays 2,4 times the scale; a spouse of ordinary means multiplies by 1.

Why the region decides the real bill

The ISD is ceded to the comunidades, and art. 48 of the Ley 22/2009 lets each of them set its own reductions, scale, coefficients, and deducciones y bonificaciones. That last word is where the drama lives, because a bonificación is applied to the final cuota. Three verified examples show the range:

• Madrid (DL 1/2010, art. 25): a 99 percent bonificación on the cuota for Grupo I and II heirs, and, since 1 July 2025, 50 percent for Grupo III.
• Andalucía (Ley 5/2021, arts. 39 y 40): a 99 percent bonificación for Grupo I and II, both mortis causa and for lifetime gifts.
• Cataluña (Ley 19/2010, art. 58 bis): 99 percent for spouses, and for the rest of Grupo I and II a sliding scale that starts at 99 percent (Grupo I) or 60 percent (Grupo II) on the first 100.000 € of base and falls bracket by bracket, down to a marginal 20 percent and 0 percent respectively on the portion above 3.000.000 €. Opting into most other reducciones forfeits the bonificación, so the two routes have to be compared, not stacked.

País Vasco and Navarra sit outside this system altogether: under the Concierto and Convenio, the ISD there is a «tributo concertado de normativa autónoma», collected by the Diputaciones Forales or Navarra under their own laws when the deceased was habitually resident there. None of the state figures on this page apply to them.

The upshot: where the deceased had habitual residence effectively decides the bill, not where the heirs live. Two spouses inheriting identical estates can face a near-zero bill in one comunidad and tens of thousands of euros in another. The 17-comunidad comparison puts every region in one table, with dedicated pages for Madrid, Andalucía, Cataluña, Valencia, Galicia, País Vasco and Murcia. Always check the current rules of the comunidad concerned, because bonificaciones move with almost every autonomic budget.

Where this fits in the process

The tax is step five of the herencia: after the will or declaración de herederos, after accepting or renouncing, usually alongside the partition. Renouncing cleanly means never becoming a taxpayer for that share; accepting and passing it on means two taxable events. And the legítima decides how much of the estate each heir's base imponible even contains.

This page is general legal information about Spanish tax law and does not constitute legal advice in an individual case. The controlling texts are the current versions in the BOE and each comunidad's consolidated tax rules, which change frequently.