Portugal joined the Hague Apostille Convention on February 4, 1969. Following this, a Portuguese document is acceptable in all member countries of the Convention once it bears an apostille. If it is for a non-member country such as UAE, it has to be attested by the concerned local authorities in Portugal, super legalized by the UAE Embassy in Lisbon, and in the end, by the Ministry of Foreign Affairs in UAE.

Portuguese documents can only be attested on originals, unlike other European countries where copies can be attested. Certified copies will not be accepted by the ministries or embassies located in Portugal.