It is not a requirement that you have a Spanish will, but it
could be an advantage, especially for those who have
officially moved from their home country. A will will always
make it easier for everyone if something were to happen.
Whenever you have valuables in Spain. (house, bank account
What you need;
A valid passport or your residencia, the birth date etc. of
those who will inherit.
Notarius Publikus (Notary Public). But it is necessary to
first contact a lawyer or consultant who can write wills.