Are Roman Catholics allowed to receive Communion more than once per day? If not, why not?
Yes, they are. However, with that being said, they are not encouraged to do so. The only time that it is suggested that people receive more than once a day, is if they are going to two different celebrations.
By that I do not mean two different Masses on Sunday, but for two different reasons. Examples would be Saturday morning Mass for Saturday, and then in the evening for Sunday. Another example would be going to the daily Mass, and then also going to a Wedding or a Funeral.
In any case, a person should never receive Communion more than twice in one day. Exceptions to this rule go only to priests. Many times we have two Sunday Masses, and sometimes three or four. We are to receive the Body and Blood of our Lord at each Mass that we celebrate. Of course we also should not celebrate more than two Masses on weekdays, or three on weekends without there being some good reason.God Bless, Fr. Ray