Are Catholics married in a civil ceremony still permitted to receive communion? A couple was married in a civil ceremony.  They attend Catholic Church and are Catholic.
Are they permitted to receive Communion at Mass, per Catholic Church teachings?
A Catholic "married" in a civil ceremony is not in a valid marriage—unless they have regularized their marriage, thereby respecting the 6th precept of the Church on obeying the Church's marriage laws. If that Catholic is cohabitating and having sexual relations, he or she is committing fornication, which is a mortal sin. Receiving Communion outside of the state of grace (i.e., with a mortal sin on one's soul) is very dangerous:

1 Cor. 11:27:


  Therefore whosoever shall eat this bread, or drink the chalice of our Lord unworthily, he shall be guilty of the body and of the blood of our Lord.