Hi johnzx
I AMA resident so it doesn't apply to me, but I do post on a number of forums, and I have a reasonable knowledge of the tax situation in Spain, so I generally post in responses to questions. However, if I believe that a post is wrong, I will say so, as I also believe that many people read the forums without ever joining, or asking questions, so, particularly as you seems to be a prolific poster, with some great, informative replies, they will take what you say as correct, and I believe it is fundamentally wrong, which is why I asked where it said so on the Hacienda site.
I did read some of your other posts on this yesterday, and saw the post about your friends bank account, although I recall (but I can't find the post now), they they released it when she completed a non-resident form. This to me seemed to clarify that by registering, they do not think you are tax resident, but, until you complete the form, the bank should consider you as a resident, and deduct tax from any interest they pay you. This is very different from being a tax resident, and having to submit a declaration on all your worldwide income. You have already pointed out the circumstances when you could be a tax resident if you spend less than 183 days in Spain, which is to do with centre of economics interests etc
I'm sure Mijas Town Hall provide great information, but I'm not sure I would rely on them for tax advice. As far as Blevins Franks are concerned, the quote below is from their website, which I think makes it pretty clear, registration is nothing to do with tax status.
"EU, EEA (European Economic Area) and Swiss nationals have the right to reside in Spain for more than three months a year. This is provided they apply in person at their local Oficina de Extranjeros or a designated police station, within three months of arrival. They are then registered in the Central Register of Foreigners.
Spain has now introduced new residency rules for all EU/EEA/Swiss citizens. The basic rule above still stands, but they have tightened up the requirements.
Note that these new measures have no bearing on whether you are a tax resident in Spain or not. Tax residence is a separate issue and assessed on different criteria. You can be tax resident in Spain even if you do not apply for a formal residence permit. It is your responsibility to register for, and pay, tax if you meet one of Spain’s tax residence rules. The authorities are cracking down on people who meet the residence rules but have not been paying tax in Spain."