When they book online, as well as all their details you ask them to enter a pin code that will be unique to themselves (could be longer/could be shorter) - this becomes their 'key' - they enter/quote this every time they come into contact with the business, either verbally or online.
When they then turn up in person they should know this code, and this is therefore their proof.
Right. I've got it.
When they book online, as well as all their details you ask them to enter a pin code that will be unique to themselves (could be longer/could be shorter) - this becomes their 'key' - they enter/quote this every time they come into contact with the business, either verbally or online.
When they then turn up in person they should know this code, and this is therefore their proof.
Do I win?