Re: Changing Temporary TIE to Permanent TIE
 

I’m now no more enlightened as to what we should do. It seems no-one really knows what the actual situation is in practise as it hasn’t been tested yet.
I am considering making an appointment at our local (Ayamonte) National Police Office, taking all the paperwork with me and see what happens.

Re: Changing Temporary TIE to Permanent TIE
 

Sorry to hear above info was confusing. Regardless of above disagreements about technicality on perm residence, if you already have qualifying 5 years of residence, you should apply for perm residence at local NPO, as you seem intend to do. Just in case, bring tax returns for last 5y and any bills covering those 5y.

Re: Changing Temporary TIE to Permanent TIE
 

According to Spain's Brexit FAQ (probably difficult to get more official unless you find the text of the law itself), you can exchange your card from the date you have permanent residency.

• English version - last question on last page.
• Spanish version - same again, last question on last page.

But then again there's always the chance your autonomous community's police may not have implemented the policy or may not consider it a priority.