Spanish Inheritance Tax Deadline: Six Months, Extensions and Common Mistakes

When a family member dies, preparing the inheritance can take time: locating the will, obtaining certificates, identifying assets and coordinating the heirs.

The tax calendar, however, does not necessarily wait for these steps to be completed.

As a general rule, Spanish inheritance tax (Impuesto sobre Sucesiones) must be filed within six months of the death. To request an extension, you must act earlier: within the first five months.

At MH Legal & Seguros we explain how to organise these deadlines, especially where the inheritance involves documents or people resident in other countries.

From when the inheritance tax deadline runs

The general period starts on the date of death. Where a person has been declared dead by a court, the date on which that declaration becomes final must be taken into account, in accordance with the applicable rules.

It should not be counted from:

• Receipt of the will.
• The first appointment with the lawyer or the notary.
• The agreement between the heirs.
• The signing of the deed.
• The sale of the inherited assets.

To prepare the file, note the starting date and confirm the exact due date with the competent administration. The six months should not be turned into an informal estimate of days.

When to request an extension of the inheritance tax deadline

An extension allows the filing period to be extended by a further six months, but it must be requested within the first five months of the initial period.

The extension begins when the ordinary six months end, not when the request is filed. It is not granted this way if it is requested after the first five months.

The fifth month is an important checkpoint, even though the deadline for filing the tax has not yet expired.

If you foresee difficulties in completing the documentation, review the possibility of an extension with sufficient time.

Which documents usually accompany the request

The request must be addressed to the competent administration and follow its procedure.

As a basis, the following should be prepared:

• Death certificate.
• Identification and address of the declared or presumed heirs.
• Relationship to the deceased, where known.
• Situation and approximate value of the assets and rights.
• Reasons justifying the request.
• Representation and notification details, where applicable.

In the non-resident files handled by the AEAT, there is a specific electronic form and the possibility of filing a written request through the registry with the corresponding documentation.

Keep the proof of filing and review any later notifications.

Does the extension have a tax cost?

The extension carries late-payment interest for the period running from the end of the ordinary period until filing, on the applicable terms.

Obtaining more time therefore does not mean that the delay beyond the six months is tax-neutral.

Before requesting it, it is worth assessing which documentation is missing and how much additional time may be needed.

What happens if no reply arrives

The Regulation provides that, one month after the request without notification of an agreement, the extension is deemed granted.

This rule must be assessed together with filing within the deadline and the requirements of the file. Keep the request and check that no notification has been received through the enabled channel.

What to do if the deed is not yet ready

The tax calendar should not be left waiting for the notarial signing.

In the form 650 (modelo 650) files handled by the AEAT, the documentation may include, in the absence of a deed of acceptance, an inventory of assets and heirs with the required information.

This does not mean that any incomplete document allows the tax to be filed correctly. You must review what information is available and how to comply with the obligations without confusing the tax filing with the civil formalisation of the inheritance.

Foreign documents: prepare two coordinated calendars

In an international inheritance, certificates, translations, powers of attorney or succession documents from another country may be pending.

To organise the work, it is useful to keep two calendars:

Both must be coordinated from the outset. If a document is missing, identify which step depends on it and which actions can move forward while it is obtained.

Do not assume that processing abroad automatically extends the Spanish deadline.

Does a disagreement between heirs suspend the deadline?

A family disagreement should not by itself be treated as a tax suspension.

The Regulation contemplates certain situations related to court proceedings, but it also excludes actions that do not produce that effect. The specific procedure, its dates and its tax impact must be reviewed.

If there is litigation, inform the professional preparing the tax. It is not enough to know that “the inheritance is in dispute”.

What to do if the six months have already passed

The first step is to review:

• Whether an extension was requested and what effect it had.
• Whether any circumstance alters the calculation.
• Which documentation is prepared.
• Whether the Administration has issued a requirement.
• What the result of the self-assessment would be.

The consequences are not identical in every case.

Where the late-filing regime without a prior requirement applies and there is an amount to pay, the General Tax Law (Ley General Tributaria) provides for surcharges linked to the delay. Filing after a requirement calls for a different analysis.

It is not advisable to keep waiting simply because the deadline has passed. How to regularise the position and deal with the pending steps must be assessed.

An extension to file and a deferral of payment are not the same

Needing time to gather documents and needing finance to pay are different problems.

It should not be assumed that requesting an extension resolves any payment difficulty. If liquidity is short, the available options and their requirements must be reviewed separately.

Communicating this circumstance at the outset allows the file to be organised better.

Frequently asked questions about the inheritance tax deadline

Can I request the extension during the sixth month?

The ordinary request for an extension must be filed within the first five months. It is not advisable to wait until the last month of the general period.

Does the extension give me six months from the date I request it?

No. The extension starts when the ordinary six-month period ends.

Does living abroad automatically give me more time?

No. The AEAT also sets the general six-month period for the non-resident files it handles.

Can I wait until I sell the property to file?

You should not rely on that. The tax calendar must be organised from the date of death, regardless of any sale plans.

Does filing the tax end all the inheritance formalities?

No. The succession documentation, the distribution of the estate and, where applicable, the registration of the assets must also be coordinated.

Organise your inheritance deadlines from the start

An early review makes it possible to identify due dates, anticipate documents that are difficult to obtain and consider an extension before its application period ends.

At MH Legal & Seguros we advise international clients with inheritances in Spain. We review the position of the file and coordinate the documentary and tax preparation with the professionals who need to be involved.

Contact our team to review the deadlines and organise your inheritance in Spain.