There is a tie-breaker rule will be applied when team are sharing the same points after all group matches are completed.
The rule is based on paragraph 8.07 and 8.08 of UEFA policy document, which quoted as follows :
If two or more teams are equal on points on completion of the group matches, the following criteria are applied, in the order given; to determine the rankings:
a) higher number of points obtained in the matches among the teams in question;
b) superior goal difference in the matches among the teams in question (if more
than two teams finish equal on points);
c) higher number of goals scored in the matches among the teams in question (if
more than two teams finish equal on points);
d) superior goal difference in all the group matches;
e) higher number of goals scored in all the group matches;
f) position in the UEFA national team coefficient ranking system (see Annex I, paragraph 1.2.2);
(1) Spain 43,116
(2) Netherlands 40,860
(3) Germany 40,446
(4) Italy 34,357
(5) England 33,563
(6) Russia 33,212
(7) Croatia 32,723
(8) Greece 32,455
(9) Sweden 31,675
(10) Denmark 31,205
(11) Portugal 31,202
(12) France 30,508
(13) Republic of Ireland 28,203
(14) Ukraine 28,029
(15) Czech Republic 27,982
(16) Poland 23,806
g) fair play conduct of the teams (final tournament);
h) drawing of lots.
If two teams which have the same number of points, the same number of goals scored and conceded play their last group match against each other and are still equal at the end of that match, the ranking of the two teams in question is determined by kicks from the penalty mark (Article 16), provided no other teams within the group have the same number of points on completion of all group matches. Should more than two teams have the same number of points, the criteria listed under paragraph 8.07 apply.
It looked like that the tie breaker rule for this tournament will stop at point f), because there are no countries that are sharing same coefficient.