Most of the churches I've been to have not had a formal "check in" process, but they do have a membership process (people can be added to the member list, and a

Most of the churches I've been to have not had a formal "check in" process, but they do have a membership process (people can be added to the member list, and are then allowed to vote for church leadership committees and such) and cards for guests to fill out if they want to be contacted. Childcare (nursery) often has a check-in process specifically relating to who is and isn't allowed to pick up your children.