In my experience, this form of expense management is a relatively new development. Not so long ago, I had a company linked corporate card. Credit card transactions are already labeled with the type of purchase. You have to submit a report that corresponds to the actual charged amount. Additionally, they get all the bills with their hotel partner to cross reference the transactions with the credit card and the submitted expense. Flights etc worked the same way. Those are now additionally tracked in the company travel relationship portals which accomplish the block chain without the block chain. None of this requires a global immutable currency ledger or anything like that to accomplish their goal: just get some reasonable transaction validation long enough to process the expense then never look at it past an audit. Later, they also made people eat from the same hotel and negate the issue for meal expenses. It's just not a technology problem. If it were, they would just demand more granularity from the credit card company and the employee and reject things out of policy.