This is what I did and it seemed to work fine for us. I tried to find a picture or the design I used to show you but cant seem figure out where I have it saved at the moment.
I actually printed the season pass ticket myself. I did them on card stock. This way, you do not need to print more than you actually need. We never sold a huge amount of season passes, but that may be different for you. If you feel you need hundreds of season passes than it would be cheaper to have them printed.
The pass pretty much show the haunt name, address, phone number, web address and open dates. We also excluded some special event dates from the season passes which was also clearly represented on the card. It also mentioned they were not valid with any other offers or discounts. Then, at the bottom of the card was a place for their signature, and photo I. D. number and for the ticket sellers signature or initials. Both signed the card and the ticket seller wrote down the I. D. number. It was printed on the ticket that they must bring their same I. D. and the season pass with them each visit and check in at the ticket window. On their initial purchase, the ticket seller would keep track on our nightly tally sheet of how many season passes were sold. On each follow up visit after verifying their card and matching I. D. instead of throwing off our number count by giving them a regular admission ticket, the seller would simply give them a courtesy pass which we always kept on hand anyway for special visitors or other haunted houses.
It was pretty simple and that way you know that they are not passing on the season pass to other people. We also kept the price reasonable to encourage people to buy them. We charged $5.00 less than if they had purchased a second ticket on another day. So, our regular admission price was $15.00 and the season pass only cost $25.00. So it was cheaper than buying two tickets for the year. I know many owners feel it should be more like the value of 3 or four trips through, but I say why? You have already made your money from them on the first ticket and this just encourages them to come out more times in the season than perhaps they would have otherwise. Hopefully, they bring different people with them each time to go through, making you even more money off that simple gesture of a reasonable ticket price. Plus, I always took the fact that they wanted season passes as a huge compliment. It means that before even seeing what your show is like that season, they are such a fan of your attraction that they are willing to pay the extra to come back multiple times.
I am sure others have a better way of doing it. And I'm sure someone will point out the flaws in my system, but it worked for me and was very easy to do.
Hope that helped. If I was not clear about something feel free to PM me. I really do not post on many subjects here anymore unless I feel I have something very useful to add to the topic and do not check in very often anymore.
1986-1997 (Mutilation Mansion,) 1998 (Screamers Haunted House,) 1999 (Evil Intention Haunted House,) 2000-2001 Concept Creator/Business Partner (Urban Legends Haunted House,) 2002 Floor Plan Designer and Consultant for a (Haunted Barn) Owners had city challenges & were never able to open, 2002 Floor Plan Designer/Construction (Fright Nights Haunted House) 2003-2012 Now retired Owner (Deadly Intentions Haunted Attraction)