TAXATION - AS PER CANARY ISLAND TAX AUTHORITY, GESTION TRIBUTARIA (HACIENDA)
As a non-resident you are NOT TAXED ON WORLDWIDE ASSETS, only if you become a FISCAL RESIDENT. Even if you declare the asset in the UK you would NOT be taxed there unless you declared it as a source of income, otherwise there is NO dual taxation on this. When selling, If you declare your asset here (the apartment) you DO NOT pay Capital Gains in the UK. This is why a 3% retention is made on non fiscal resident sales, unless they produce a certificate from the Spanish tax office declaring all their tax affairs (in Spain) are up to date.
TAX CALCULATION FOR NON RESIDENTS OWNING ASSETS IN THE CANARY ISLANDS
Recently the tax percentage has gone down from 24.5% to 19.5%, but here is how it works; you take 1.1% of the valor catastral (ratable value) and then multiply it by 19.5%, the resultant figure is the tax you pay annually.
Example: if the ratable value (not purchase price) is say, 100,000 Euros, your annual tax liability is:
100,000 x 1,1% = 1,100 x 19.5% = 215.50 Euros p.a.
This information was correct at the time of going to print; you are advised to seek advice from a qualified tax specialist.