For those of you who did invite entry system…

For those of you who did an invite entry system, how did you do it? We have around 175 planned guests and I was considering asking people to give their invites (or something else) at the door so that we are not getting random people not on the list?

Unfortunately, yes, I am extremely worried FH’s family will just show up that weren’t invited because it’s a common thing for them to do.

Any ideas?