A great deal of misinformation is currently in existence surrounding the benefits of a foreign national preparing a Spanish Will. The starting point is the Spanish civil code which expressly allows you to leave your Spanish assets in accordance with the national law of your country of origin. For example, a British person is free to leave his/her estate to whoever they wish and would not be obliged to leave a proportion of the estate to family members as is required of a Spaniard.
Whilst there is no obligation to prepare a Will in Spain , the existence of a Spanish Will is a cost effective means of simplifying the handling of your affairs. I have come across people who intend to rely upon their English Will (or, even worse, English intestacy rules where there is no Will at all) to deal with their Spanish estate. Unfortunately however, no action can be taken in Spain until the probate of your English estate has been finalised. This can take a very long time - irrespective of whether your English Will or affairs are complicated or straightforward. There is also the expense of preparing an official translation of the English Will and its legalisation to bear in mind, which together will cost significantly more than preparing a Spanish Will in the first place.
A closely related topic is inheritance tax. Many people are aware that the Spanish authorities impose tax penalties if matters are not dealt with quickly. You have only 6 months to pay the taxes due on the deceased's Spanish estate following the date of death, failing which a surcharge will be applied and interest will start to accrue. It is rare for the English probate to be dealt with in time to allow this deadline to be met. In addition, many people mistakenly believe that by simply waiting four and half years before informing the Spanish authorities of the death, there will be no tax to pay. This is a high-risk approach and also means that the estate (usually comprised mainly of a house) cannot be sold or borrowed against during this period.