As mentioned earlier, the contest is open only to the grand prize winners of the six member European choral competitions in the previous year. In other words, if a choir wins the grand prize in any of the six cities' choral contests, it is eligible for then next year's GPE. Consequently, this also means that, unlike other choral competitions, the GPE does not solicit participants to the contest; no choir may directly apply or audition in order to join the GPE. If an eligible choir backs out, a substitute choir may take its place; as a penalty, any choir that backs out will not be eligible to compete in any of the six qualifying contests for the next year.
No choir may win the grand prize in more than one qualifying competition in a single year. For example, if a choir is named the grand prize winner in Arezzo, it is automatically disqualified to compete in the contests from the five remaining cities for the rest of the year.
There are no specific regulations prohibiting a former finalist (or even a former laureate) from competing in (or even winning again) the GPE more than once. The Philippine Madrigal Singers (laureate of the 1997 GPE) have won the 2006 Florilège Vocal de Tours, going on to win the Grand Prize in 2007 in Arezzo, Italy. In the same competition, the Madrigal Singers competed with the Vesna Children's Choir (laureate of the 2000 GPE), who won the grand prize of the 2006 Tolosa competition.