Are there guidelines that priests have for refusing someone communion? When can or should they refuse to give communion? With the hot topic of polititians who support abortion going to communion, our men’s group has a discussion going on this topic. The only time I know of a priest refusing someone communion is when the person ( a non-Catholic) obviously didn’t know what he was doing. But I would believe that a priest can’t refuse communion on the supposition that he is in sin, because he doesn’t know when that person last went to confession.