Portugal is part of the Schengen Area of 25 European countries, hence nationals from a number of countries may be exempt from holding a VISA. Nationals from countries that have a VISA requirement may apply at their local Portuguese Consulate. Please indicate during the registration if you need a personal invitation to letter to attend the conference (or by email to email@example.com).
Passage through Customs is mandatory for all Portuguese or foreign travellers entering or leaving the country transporting money or goods. However, up to certain limits permitted by law, citizens are not required to declare the goods they are carrying with them. As Portugal has adopted the customs regulation of the European Union, detailed information about customs regulation, based on country of travel may be found here.