As an adult in Spain, you should make a Will irrespective of how large or small your assets are. If you were to die without a Will in Spain, your estate may be automatically disposed of under Spanish law and the law regarding obligatory heirs.
A foreign resident in Spain is usually permitted to dispose of his/her Spanish assets according to the law of his home country, provided there is a valid Will under the law of that country. If you have lived in Spain for a long time, it may be necessary for you to create a legal domicile in your home country for the purpose of making a Will.
As in most countries, dying does not free your beneficiaries from the clutches of the tax man, nor does giving your money away before you die. Spain imposes a tax on assets or money received as an inheritance or gift (impuesto sobre sucesiones y donaciones). The estates of residents and non-residents are subject to Spanish inheritance and gift tax if they own property or have other assets in Spain. Inheritance and gift tax is paid by the beneficiaries, e.g. a surviving spouse, not the deceased’s estate.