According to the article 9 of the Spanish Civil Code, the law applicable to an inheritance is determined by the nationality of the deceased. The 8th section of the referred to article specifies that, regarding the applicable law, there is no distinction made as a result of the location of the assets.
Impact of EU Regulation No 650/2012
That said, things have changed as a consequence of the EU Regulation No 650/2012 of 4th July 2012, on “jurisdiction, applicable law, recognition and enforcement of decisions and acceptance and enforcement of authentic instruments in matters of succession and on the creation of a European Certificate of Succession”.
Article 21 of that Regulation establishes, as a general rule, that “the law applicable to the succession as a whole shall be the law of the State in which the deceased maintained habitual residence at the time of death”. Where, by way of exception, it is clear from all the circumstances of the case that, at the time of death, the deceased was manifestly more closely connected with a State other than the State whose law would be applicable under the previous paragraph, the law applicable to the succession shall be the law of that other State.
According to Article 22, a person may choose as the law that governs the succession of their assets as a whole, the law of that State whose nationality they possessed at the time of making the choice, or at the time of death. This Regulation entered into force on the 17th of August 2015.
No Valid Will
As a result, if there is no valid will, that states that the testator wishes to apply the rules of their country of origin, and the testator was ordinarily resident in Spain at the time of death, the the rules of intestacy of Spain will apply.
If such rules do not apply, for instance because the testator was ordinarily resident in the UK, then the rules of intestacy local to their place of residence in the UK will apply.
Documentation Required to Process an Inheritance if no Will
In the UK it is typical, in the absence of a last will and testament, for a close relative to swear an oath and obtain 'Letters of Administration' which confer the right to deal with any assets in the name of the deceased, in accordance with the laws of intestacy.
Matters become complicated in Spain as a result of the local notary and land registrar sometimes insisting on Spanish documents, impossible to obtain from the UK.
Ultimately, some notaries will accept the Letters of Administration, duly legalised and translated by a sworn translator. Others will require a certificate of law from a legal source in the UK (such as a notary or a solicitor) which states the applicable line of succession according to the rules of intestacy of that region of the UK.
The above will be required together with a death certificate (if death took place outside of Spain then this death certificate may also need to be translated and legalised) and also identification documents relating to the beneficiaries and NIE numbers.
So, in summary, if you are planning to become resident in a European country other than the country of your nationality, such as say Spain, and you wish the rules of succession of your country of origin, say England, to apply, then you must state this explicitly in your Last Will and Testament. Otherwise, Spanish law will apply and the system of forced heirs that pre-determines the beneficiaries rather than permitting you to elect them, will apply.