It’s all to do with Spanish succession law which takes away almost all your rights to leave your assets to whom you like. They have to be left primarily to the children and the remaining spouse is entitled to nothing apart from the right to live in the family home until death.

In the past, it was generally accepted that this did not apply to foreigners who were able to use the succession law of their own country. This was always a bit vague legally, so a few years ago the EU issued a decree that, if specifically requested in the will, that the foreign law would apply. So, it is essential that you have a will for assets in the UK as well as in Spain. A combined will will create huge problems as the legal systems in both countries are very different.

The simple rule on IHT is that assets in Spain are taxed in Spain irrespective of residency. UK assets bequeathed to a UK resident will be taxed only in the UK but if a Spanish resident receives a bequest of UK assets they will be taxed in Spain. The payment of IHT is down to the recipient unlike UK law where it is the estate that is taxed, not the individual. IHT is a very complex area and the actual tax paid can be determined by your location, not by national rules. If in doubt talk to a professional.