"Everyone needs to have someone who's responsible for the aggregate spend data," he said. And you need to be able to get your hands on the evidence that proves your data's validity quickly as well, since you'll have only 15 calendar days to find evidence to support your data if it's challenged.

What that means is that companies will need a systematic way to store tracking documentation so they can be readyto present the evidence, explained Garen. “Let me tell you, you will need a really great filing system for the receipts, sign-in sheets, and lists,” he said to the audience of more than 600 at the Marriott Orlando World Center. “This cannot be in the ‘Raiders of the Lost Ark’ warehouse—you’re going to need to get your hands on this quickly. This dispute-resolution process will be huge. You’re going to have to have communications people who are dealing with these issues.”