With so many cities to be involved the European governing body is anxious to ensure that air travel will not be an issue. That is likely to be something of a headache for Cardiff, and the Welsh FA would have to argue that Bristol or even airports further afield could be used as an alternative for fans.
Dublin and Glasgow are also expected to bid to host group matches at Euro 2020, which for the first time is to be held across Europe instead of in one or two countries. The Football Association is to bid to host the semi-finals and final at Wembley, or group matches and quarter-finals if that is unsuccessful.
Rival bids for the final are expected from Istanbul - the favourite if it is unsuccessful in its 2020 Olympic bid - plus Madrid, Berlin and Rome.
Two cities with smaller-capacity stadiums will be among the 13 chosen as Euro 2020 hosts in an effort to broaden the reach of the tournament, according to sources close to the process.
Officials drawing up plans for the tournament have decreed that two host cities can have a stadium capacity as low as 30,000, that 10 stadiums will have a 50,000 minimum capacity and four of those hosting the quarter-finals to have grounds of at least 60,000.
The stadium that hosts the two semi-finals and final will have to be able to seat more than 70,000 fans.
UEFA's executive committee is expected to agree to the plans at its meeting on March 28.
The idea in having two 30,000-seater stadiums means smaller countries will be able to enter the bidding - only 21 of the 53 UEFA member nations have stadiums of 50,000 or more.
Tournament planners believe that host countries will be able to play at least two of their group matches at home. UEFA will also to try to arrange groups on a geographical basis to avoid long journeys across Europe for fans.