You can, what you end up paying is another story. My corporate contract allows me to do this and even allows me to drop off a round trip rental as a one way with no penalty. When I was looking at missing my flight home at ORD I looked and it would have been $1,000 for a one way rental home with another company, National wouldn't even show me a price. My corporate travel people had me a car reserved in 20 minutes for much, much less. Ended up not needing it but nice to know that's in the contract.