If your spouse/civil partner or simply partner* are Portuguese or are from an EU country living in Portugal and legally resident here, and you wish to join them you may also apply for residency as a family member of a Portuguese or EU citizen who are allowed to have residence in Portugal.
Dependant children under the age of 18 as well as dependant parents may also apply for a residency visa.
This can be a very interesting option for British citizens – post-Brexit – if you have access to an Irish or other EU passport, by virtue of having a parent or grandparent who was born in that country.
While the holder of the passport will have an automatic right to reside in Portugal – by virtue of their EU citizenship - their partner and dependant children can use this visa application process to also reside legally in Portugal. The visa also grants the right to work in Portugal.
* Family reunification is allowed in relation to a non-marital partner whether the partner is inside or outside national territory, provided that the relationship is recognised under the law (Regulation Decree Nº84/2007, November 5.