France, Turkey and Italy, the three candidates to stage the 2016 European championship, formally handed over their bids on Monday in a ceremony at UEFA headquarters.
European soccer's governing body said in a statement that more than 100 criteria, from stadiums and accommodation to legal matters, would be examined before the host nation is chosen in Geneva on May 28.
Sweden and Norway also put forward a joint candidature but withdrew in December after their governments said they would not be providing the money needed for investment in stadiums.
It will be the first European championship to feature 24 teams, eight more than will compete in 2012 when Poland and Ukraine co-host the event.
"Today marks a very important milestone in the bidding procedure, as it finalises the period of hard work and enormous commitment by each bidder," said UEFA's national teams competitions committee chairman Gilberto Madail.
"For the final tournament, hundreds of thousands of people visit the host country in order .....watch matches and celebrate together," he added.
"On television, millions of people worldwide follow each match. Not only does this have a positive impact on the tourist industry, and thus on the economy of the country as a whole, it also supports the social aspect of football by bringing people together."
Italy, whose failure to land the 2012 tournament was blamed on a hooligan problem and the crumbling state of its stadiums in Serie A, has already said it will stage matches in nine different cities.
Turkey, which has never staged a major international soccer tournament, has promised to bring passion to the event.
Italy hosted the tournament in 1980 and France four years later, eight teams taking part on each occasion. Both countries have each staged two World Cups, Italy most recently in 1990 and France in 1998.