All tax residents in the Canary Islands have to declare their assets outside of Spain, including property, investments and bank accounts if their value exceeds €50,000. The compliance rules around this are quite complex and we do recommend you ask for advice if you think this applies to you. The declaration has to be made using model 720, which is submitted in March for the previous year.
Once you make the declaration, you only have to make a new one if there’s an increase of €20,000 or more.