Spanish inheritance tax is due within six months of the date of death. Miss the deadline without an extension and you face a 5%–20% surcharge plus interest. This page is the full deadline runbook — Modelo 650 filing, extension procedure, regional variations, what to do if you miss the date, and the step-by-step process Platinum Legal Spain runs for every cross-border estate.
The six-month rule is the single most important practical fact in Spanish inheritance. Article 67 of the Reglamento del Impuesto sobre Sucesiones y Donaciones (Real Decreto 1629/1991) fixes the voluntary payment period at six months from the date of death. Article 68 provides a single six-month extension, which must be requested within the first five months. Miss both and the estate enters the extemporánea (late) regime: surcharges of 5%, 10%, 15%, or 20% depending on delay, plus daily interest, plus potential sanctions if the Agencia Tributaria considers the delay negligent.
The deadline is fixed. It runs from the date of death, not from the date the heirs discover the estate, not from the date probate is obtained in the deceased's home country, not from the date the Spanish notarial escritura de aceptación y adjudicación is signed. This catches almost every foreign family dealing with a Spanish estate for the first time. UK probate alone routinely takes 4-8 months; German Erbschein 3-6 months; Dutch verklaring van erfrecht 2-4 months. If the foreign procedure is not running in parallel with the Spanish six-month clock, the deadline is missed by default.
Extensions under Article 68 are granted routinely if requested in time. The written request (escrito de solicitud) must reach the competent regional tax office within the first five months, with supporting documentation on the estate's complexity, pending foreign probate, or outstanding valuations. The extension is for a single additional six months, taking the total window to twelve months from death. No second extension is available.
This page walks through the deadline rules, the regional variations (each autonomous community administers its own IHT, and some — notably Catalonia — have small procedural differences), the Modelo 650 filing mechanics, the extension procedure, what happens if you miss the date, and the standard process Platinum Legal Spain runs to ensure no foreign family ever loses the bonificación through a procedural failure.
Six months from death to file Modelo 650. One six-month extension available if requested in the first five months. Regional autonomous communities administer the tax — the regime and bonificación follow the autonomous community of the deceased's habitual residence (or, for non-residents, the autonomous community where most Spanish assets sit under the 2014 ECJ ruling).
Article 67 Reglamento ISD. The voluntary payment period is exactly six months, counted from the date of death on the certificado de defunción. The deadline does not pause for foreign probate, bank delays, or valuation disputes.
How the clock startsArticle 68 Reglamento ISD. Written request to the competent regional tax office before the end of the fifth month, supported by documentation on foreign probate timing, asset complexity, or valuation delays. Granted routinely when properly drafted.
Extension draftingModelo 650 is filed online or in person with the autonomous community's tax office. Annexes include inventory of assets, liabilities, valuations, relationship evidence, and any claimed reductions or bonificaciones. Payment is due with the return.
Modelo 650 walkthroughThe base six-month rule is national, but each autonomous community (Andalusia, Madrid, Valencia, Catalonia, Murcia, Balearics, Canarias, etc.) has its own filing forms, online portals, payment accounts, and sometimes its own deadline interpretations for edge cases.
Regional proceduresUnder Article 27 Ley General Tributaria: 1%+1% per month up to 12 months late (capped at 15%), then 15% plus interest from month 13. Voluntary self-disclosure before Hacienda contacts you halves these surcharges.
Late-filing recoverySome regional bonificaciones (notably in Madrid and Andalusia) require the Modelo 650 to be filed within the six-month voluntary window. Filing late with the 99% bonificación claimed is routinely rejected. The difference between 1% IHT and full IHT on €500k is real.
Protecting the bonificaciónThe deadline math is unforgiving but not mysterious. A death on 15 March 2026 means the voluntary deadline is 15 September 2026 and the extension request must reach the tax office by 15 August 2026. Every cross-border estate we handle has these two dates in the file from day one — the rest of the process works backwards from them.
The extension request is straightforward but must be specific. Vague references to "complex foreign estate" will not do. We reference the deceased's nationality and domicile, identify the foreign probate procedure in progress (UK grant of probate, German Erbschein, Dutch verklaring van erfrecht, French acte de notoriété, Italian dichiarazione di successione), attach documentary evidence of foreign filings made, and project the completion date. Tax offices are used to these requests from cross-border estates and grant them routinely.
Regional autonomous communities differ in administration. Andalusia uses the Agencia Tributaria de Andalucía portal with its own SUMA system. Madrid runs through the Comunidad de Madrid's portal directly. Catalonia has the ATC (Agència Tributària de Catalunya) with specific Catalan-language forms. Valencia runs through the ATV. Balearics through the ATIB. Each has its own online certificate requirements (Cl@ve, certificado electrónico, or regional equivalent). Foreign heirs frequently stumble on the digital certificate step alone.
We log the date of death from the certificado de defunción, calendar month 5 (extension deadline) and month 6 (voluntary filing deadline) immediately, and begin asset inventory and foreign probate coordination in parallel from day one.
We produce the inventory of Spanish and worldwide assets (for Spanish-resident deceased), liabilities, valuations (vivienda habitual at catastral+correction, securities at day-of-death quotation, bank accounts at closing balance), and gather relationship and marital property evidence.
By month 5, if foreign probate or valuations are still pending, we file the Article 68 extension request with the competent regional tax office. Written escrito de solicitud with supporting documentation — granted routinely when drafted correctly.
By month 6 (or month 12 if extended), we file Modelo 650 with the competent autonomous community tax office, attach all annexes, claim applicable bonificaciones and reductions, and settle the net IHT payable. Registro de la Propiedad and bank release follow.
Article 67 of Real Decreto 1629/1991 sets the core rule: "El plazo de presentación de los documentos o declaraciones a que se refiere el apartado anterior será de seis meses, contados desde el día del fallecimiento del causante." Six months from the day of death — not from when notified, not from when probate is granted, not from when the Spanish notary issues the escritura. The six-month clock is absolute.
Article 68 provides the extension mechanism. The request must be filed "antes de que expire el plazo de los cinco meses primeros, contados desde el día del fallecimiento". Five months from death to get the request in. The extension granted is a further six months, taking the total filing window to 12 months from death. Only one extension is available. The request must be reasoned ("motivado") — which means it must explain why the original six-month window is insufficient. Foreign probate, complex asset valuations, and disputed heirship are all accepted reasons.
Modelo 650 is the Spanish IHT declaration. It has a main form plus specific annexes: Anexo A (inventory of assets and liabilities), Anexo B (share acquisition details), Anexo C (life insurance), Anexo D (business and professional activities), Anexo E (real estate details), Anexo F (motor vehicles). Each regional autonomous community has its own version of Modelo 650, though the structure is harmonised. The filing must be in Spanish (Castellano or regional co-official language where applicable).
The valuation rules bite here. Real estate must be declared at the higher of (a) the cadastral value multiplied by the regional coefficient (valor de referencia since 2022), (b) the escritura price if recently acquired, or (c) the price disclosed by the Agencia Tributaria in its valuation database. The 2022 valor de referencia changes made this much harder to negotiate — the tax office publishes a value and challenging it requires a formal tasación pericial contradictoria (expert cross-valuation), with costs borne by the heir.
Late-filing surcharges under Article 27 Ley General Tributaria apply cumulatively. If the return is filed within one month after the deadline, the surcharge is 1% plus 1% for each additional month (so 1% at one day late, 2% at one month and a day, etc.), capped at 15% at twelve months. After twelve months, the surcharge becomes 15% plus late interest (currently 4.0625% annually) from month 13. If the return is filed as a voluntary self-disclosure before the Agencia Tributaria initiates any check, these surcharges are reduced by 25%. If the heir pays within the payment window assigned after filing, they are reduced by a further 25%.
Bonificación loss on late filing is the nastier risk. Madrid's Article 22.4 bonificación of 99% applies "siempre que se presente el impuesto en el plazo de seis meses o en el plazo concedido de prórroga". Andalusia's bonificación under Decreto-Ley 1/2019 similarly conditions on timely filing. A foreign heir who discovers the estate nine months after death and files without extension risks losing the entire bonificación — a 99% saving on a €500k base, around €40k of tax that disappears from procedural failure.
The regional dimension matters for procedural details too. In Andalusia, the Agencia Tributaria de Andalucía requires Form 650 plus annexes to be submitted via SUMA or in paper at a delegation. In Madrid, online submission via the Comunidad de Madrid portal requires Cl@ve PIN, Cl@ve Permanente, or a certificado electrónico. In Catalonia, the ATC requires identidad digital via idCAT or Cl@ve. Foreign heirs typically lack Spanish digital credentials and must either appoint a Spanish representative (apoderado) or obtain an FNMT certificate for non-residents — a 2-4 week process in itself.
Timelocks at banks and registries compound the deadline problem. Spanish banks do not release deceased's balances until the Modelo 650 has been filed and either paid or a no-assets-held certificate issued by the tax office. The Registro de la Propiedad does not process title transfer until the filed Modelo 650 is produced. This means that even within the six-month window, heirs cannot access funds to pay the tax — typical solution is a short-term loan secured on the assets, or payment from the heir's own resources with later reimbursement from the estate.
Non-resident deceased estates have a slight deadline twist. Where the deceased was not Spanish-resident, the Modelo 650 is filed with the Oficina Nacional de Gestión Tributaria in Madrid, not with a regional authority. Since the 2014 ECJ ruling and 2018 Spanish domestic reform, non-resident heirs can elect to apply the autonomous community regime of the region where most Spanish assets are located. This election is made on Modelo 650 itself and cannot be changed retrospectively — filing the wrong election can cost the bonificación.
Split payment (fraccionamiento) and deferral (aplazamiento) are available under Articles 37 and 38 of the Reglamento ISD. Fraccionamiento up to five years with normal interest; aplazamiento up to one year with partial interest waiver. Both require a formal request with supporting documentation. They do not extend the filing deadline — the Modelo 650 must still be filed within six months or twelve (with extension). Only payment is deferred, not declaration.
Practical deadline management at Platinum Legal Spain: every estate file opens with an extension-readiness assessment in the first week. If foreign probate is unlikely to complete in four months (common for UK, US, Canadian, Australian estates), we file the extension request proactively in month three or four, not the last-minute rush at month five. This leaves buffer room for any follow-up questions from the tax office, and documents diligence if any late-filing issue arises later.
Six months. One extension. Miss the window and the bonificación can evaporate — along with 99% of what the plan was designed to protect.
Request a Spanish IHT Deadline Estate ConsultationParents resident in Spain with children in Spain; non-resident property owners leaving Spanish assets to heirs abroad; surviving spouses, siblings, aunts and uncles, grandparents — every cross-border configuration follows a different rulebook.
English deceased, Spanish villa €600k. UK grant of probate issued month 7. Without extension, Modelo 650 would be late. We filed the Article 68 extension in month 4 with UK grant application evidence; extension granted; Modelo 650 filed month 11 with Andalusia 99% bonificación intact.
Dutch deceased, assets in Netherlands, Belgium, and Spain. Dutch verklaring van erfrecht month 3, Belgian déclaration de succession month 5, Spanish Modelo 650 required month 6. Extension filed to align all three procedures; Spanish filing month 10 with full documentation.
Foreign heir learned of Spanish flat 8 months after death. Already past extension deadline. We filed immediately as voluntary self-disclosure before Agencia contacted heir, minimising surcharge to 7.5% net (double-reduced), preserving bonificación where regional rules permitted.
German deceased, Spanish assets split between Madrid flat and Málaga villa. Modelo 650 filed in Madrid (ONGT) with election of Madrid regime (flat higher value) — Madrid 99% bonificación applied to full estate. Wrong election would have applied Andalusia's rules only to the villa.
French deceased, Spanish bank balance €180k. French acte de notoriété month 2, but bank refused release until Modelo 650 filed. Interim funding from heir's resources paid the IHT in month 5; bank released balance month 6 on presentation of filed Modelo 650.
Heir filed extension request month 5 day 28 with weak reasoning. Tax office rejected the request. Modelo 650 filed month 6 day 3 — three days late — with 1% surcharge. Full bonificación preserved because Madrid rules allow the surcharge period to count as within the extended window for bonificación purposes.
Foreign probate can take 6-12 months. Starting the Spanish process only after the foreign procedure completes almost guarantees a missed deadline. Work both procedures in parallel from week one.
The extension request must arrive before the end of the fifth month. Filing on month 5 day 28 is fine; filing on month 6 day 1 is too late — no extension, surcharges on filing, bonificación at risk. Diary the five-month date, not the six-month date.
Extensions are granted routinely but are not automatic. The request must be in writing, reasoned, and supported. Unreasoned requests can be denied, leaving the heir in the surcharge zone.
The competent autonomous community is the one where the deceased had habitual residence (for Spanish-resident deceased) or where most Spanish assets sit (for non-resident deceased). Filing in the wrong community requires re-filing and can trigger penalty risk.
Most regional bonificaciones require timely filing. Filing late with the 99% claimed is routinely rejected. The bonificación saves tens of thousands — losing it through a procedural failure is catastrophic for the client.
Foreign heirs need a Spanish FNMT certificate or Cl@ve credential to file Modelo 650 online in most regions. Obtaining this takes 2-4 weeks. Start the certificate application in week one of the case, not week twenty-four.
Full worldwide IHT in Spain, Modelo 650 with competent autonomous community (usually where deceased lived). Bonificaciones on the full worldwide base. Six-month deadline, extension if foreign probate requires.
Spanish IHT on Spanish-situs only. Modelo 650 filed at ONGT with regional regime election for the autonomous community where the Spanish property is located. Six-month deadline identical.
UK executors, German Testamentsvollstrecker, Dutch notaries, French notaires handling international estates. We provide the Spanish leg: Modelo 650, extension, Spanish will coordination, bank and registry release.
Estates discovered late, foreign probate delays, executor disputes. We run voluntary self-disclosure to minimise surcharges, coordinate bonificación preservation arguments where regional rules permit, and negotiate with the Agencia Tributaria.
Estates where the deceased held multiple nationalities or where heirs are in different countries. We coordinate all national succession procedures with the Spanish six-month window as the anchor point.
Estates with Spanish and foreign business assets, requiring valuation of shares, continuing operations, and application of Article 20.2.c 95% family business reduction alongside regional bonificaciones.
Brussels IV applied, wills drafted, Spain and Spanish tax positions coordinated, deadlines tracked.