How to move to Catalunya

As long as you do not spend more than 90 day PERMANENTLY or a total of 183 in a year then you can be here. 

However if you make spain your main home (centre of economic activity) even for less than those periods you will be tax resident

You do not choose where you pay your taxes it is chosen by the time you spend there if you spend more than 183 days YOU HAVE to pay your taxes here, if Spanish tax office finds out you are living here without paying taxes it will cost you a lot more, even and especially if they find out years after.

marnie

You will see that I said if one moves their centre of economic activities to spain then they become tax resident in spain immediately and then the 183 day rule is superseded

Thus if plod comes to live here he will be tax resident from day ONE and with the exception of the income from rental on his property in U.K. and possibly a crown pension he will be taxable on his worldwide income in spain

Even the two exempt sums must also be declared in spain for possible top up tax on the rentals and a crown pension so that It can be taken into consideration ,  which will probably mean paying tax at a higher marginal rate.   I start paying my Spanish tax at 29% instead of I believe 19%

And just in passing.  A person living in spain must also pay tax in spain on any un-let property worldwide other than their principle home in spain.  That would include an unlet house in U.K.

Thus if plod comes to live here

Now that me smile, just the thought of Old bill in Spain.
Good points as always, John.