Thank you for the opportunity to help you with your question!
The individual in an organization that has the ultimate purchase decision authority is the purchaser.
Please let me know if you need any clarification. I'm always happy to answer your questions.
Nov 17th, 2015
I'm sorry my fingers were typing faster than my brain. Your decider is the one who has the ultimate authority for go/no-go decisions, whereas your purchaser has the actually authority for payment of products or service.