keewee01:
I can't see it being as easy as you make out as it's not as simple as that. The parties would also need to setup financial arrangements for the flow of the parking fees back to where they have to go and there would be all the "backroom" setup that 2degrees would have to do for this to work and the equipment they'd need to put in to communicate with the parking machines (which probably involves licensing rights also). It isn't as simple as "text YES to 111 to donate $3 to the PM's retirement fund" - there is much, much more to it.
Having not heard of TXT-a-Park before I googled it and I see that it is a Vodafone service, so it may well be something that VF don't want to share also - a feather in their cap if you like.
I'm not saying it is trivial but it can't be that difficult either. The company that built it would be crazy to make it difficult for the Telco to integrate. All the "smarts" will be in their part of the solution.
It's just a messaging feed and an associated billing feed.
It is a service of Cash Handling Systems NZ. http://www.cash-handling-systems.co.nz/TxTAPark.html
Vodafone was the launch Telco but Telecom joined in soon after.