1. Players are not allowed to use more than 3 accounts.
If a player sets up more accounts, those further accounts will be deleted by InfinityChess. If a player does so repeatedly, he (or she) will be restricted to use only one account.
2. During tournaments players are not allowed to use more than one account. If a player violates this rule, he (or she) will be banned from tournaments.
JoJo - Tournament Director on InfinityChess