My employer wasn’t using Concur, but rather a competitor. It didn’t have my personal card (no reason to, since business charges had to go on corporate card). My Hertz profile had my personal card and my business card. Most of the time the travel booking system and Hertz seemed to correctly create a reservation using the corporate card, but sometimes the reservations used my personal card. The personal card was the primary card, so my personal rentals wouldn’t use the corporate card.

It can’t be that uncommon of a scenario that Hertz provides business and personal rentals to the same individual and needs to hit the correct card.

Fortunately I didn’t have that many business trips, so double checking before leaving the garage was a workaround. And that was before pandemic and the “we’ll email you the paperwork” nonsense, so I either had the paperwork in the vehicle or got it at the gate.

I am not the OP, and while my business expenses were required to go on the corporate card, managers were allowed to approve expenses when Amex simply wasn’t an option. That doesn’t have to be an overseas charge - I occasionally had restaurants where Amex wasn’t accepted. That policy is probably pretty standard; they just wanted to minimize the spend going on personal cards for the purpose or earning miles and instead earning a portion of the merchant fee as kickback from Amex themselves.