No charge for returning early but there will very likely be a substantial charge for returning somewhere other than what you agreed to in you're original reservation. Change your reservation to include a return at PHX if you haven't already done so.
Contact customer support. They switched it for no cost. If you drop off and do not contact them, there will be a substantial cost. Customer support is US based and very good!
We returned our vehicle same day expected, but at an earlier time than we planned for, no extra charge for the earlier time, you will need to inquire with Alamo about the different drop off location.
No you will not.
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