Does anyone have any suggestions on how to track students to be sure they are paying?

We are having a problem with a lot of students showing up to class who are not signed up or are in the rears on paying. The loss of revenue is bad, it's not fair to the students who are paying and most importantly its a real liability issue. Currently we just use a computer program and a sign in sheet but this is not working very well at all. We are located inside a big fitness center that has over 6000 members. We are thinking about using a computer program that has a card reader like the fitness center does
so they literally have to be under contract and current or their card is declined and they can not participate in the class. anyone else doing this? any suggestions? Thanks.

Card reader thing is what most every gym does now a days, but if you don't have the money for that, you can simply make a list of who is paying and up to date, and just do a role call.

auto-pay on paypal. just like the pro membership here

We use ABC Financial they set everything up and even track down delinquent members

you can just use cards. no card no class. stamp date of membership turn into instructor after class, he checks them and puts them in front desk. students must grab card before class or else they cannot enter.

RFID Chip under the skin of your members

we use direct draft...so they dont have a choice :) lol

A card works well. They have to swipe before entering. It serves another benefit of showing who's getting rounds in. Some guys disappear and come back expecting to get promoted. Sorry man, gotta put those reps in.

Loan shark

Strict enforcement. Send an email to everyone about the issue and that u will now enforce it. This shit aint free