I travel quite a bit for work. Along the way I naturally accumulate a mixture of both personal and business expenses. Of course a lot of my travel is booked via the company and paid for using either a company credit card or via one of our suppliers who invoices us directly.
So this kind of receipt from Aer Lingus makes my head hurt:
You'd think that I'd just paid them €183.98 using my American Express card. You'd be wrong.
The actual amount I paid was €12.99 for a slightly better seat (after being on the road for 3 weeks I just wanted to get off the last plane as quickly as possible!), but you'd never be able to work that out from the email receipt that Aer Lingus send you.
Sure, they say it's the "cumulative amount", but that's not exactly clear or even remotely helpful.
In this case, for example, the rest of the ticket was booked AND paid for a couple of months ago.
BUT if I wanted to I could easily have submitted this highly misleading receipt for full reimbursement and the error might never have been picked up on.