For marriages in Portugal, the Irish Embassy will take your application in at Embassy London, and we will forward a copy of it to our Embassy in Lisbon. The Irish Embassy in Lisbon will produce the Letter of Freedom to Marry in Portuguese.
If you were born in the Republic of Ireland, you will also need to send your original birth certificate to Lisbon. The Embassy in Lisbon will then translate your birth certificate in to Portuguese.
For more information you can visit http://www.embassyofireland.pt/home/index.aspx?id=274