A voucher is money you already took, and it should spend anywhere you trade
Sold at the escape room, spent at the bar. Sold at one site, redeemed at another. A voucher that only works in the place and product it was bought for is a restriction your customer did not agree to and your gift buyer never understood.
Across venues and across kits
A voucher belongs to the organisation, not to the till it was sold at. It redeems at any venue in the group and against anything you sell, including food, drink and add-ons rather than only the headline experience.
You can fence it deliberately if you want to, to one site or one product or one season. The difference is that the fence is a decision you made, not a limitation you inherited.
Part-redeemable, and the code stays alive
Two hundred dollars against a hundred and sixty dollar booking leaves forty dollars on the same code. No new voucher issued at the counter, no manual note, no customer told the balance is gone because the system only understands one use.
Physical cards carry a QR code and a PIN, so a card can be scanned at the door and still cannot be spent by someone who photographed it on a shelf. Every redemption is a line against the voucher with the venue, the booking and the staff member on it.
Three years minimum, and a ledger from day one
Australian law sets a minimum expiry of three years on most gift cards, so three years is the floor here and a shorter date cannot be set by accident.
Unredeemed vouchers are a liability on your balance sheet, and in year two your accountant will ask what the balance is and how it moved. The ledger is there from the first voucher you sell: issued, redeemed, expired and outstanding, by venue and by period, auditable line by line rather than reconstructed from a spreadsheet the week before the return is due.