British citizen living in Portugal — Residency Certificate

For your information I got my 5 years residency in 1hr from the Camara Municipal in Albuferia with just the copy of my passport and my fiscal number. No need for any Private Medical Certificate

Relatively straight forward.  Once you visit tax office then take paperwork to municipal office.  Small charge and they "give" you residency on the spot. If I recall it is a requirement of a other EU country to provide residency upon request.

Hello,
You'll need a health insurance with a minimum of 30.000€ for hospital expenses. Most local services don't request this because they don't know the right procedure, unfortunately. If you need to get assistance from the central authorities (SEF) they will request it.