How close to the earlier departure have you been trying unsuccessfully?
What have they said when denying you?
Originally Posted by
Totoro
With mixed experience on UA gate agents' willingness to process standby for earlier flights with checked baggage...
There is some difference between standing by at the original vs at a connecting airport. In transit standby can be tougher and may require a minimum of 2 hours to switch bags (and a signed release if bags don't make it as mentioned)
Also you can run into issue at a smaller outstation where the agent is a contract agent (covering multiple carriers many times). The process tends to be a blend of air carrier policies.
United.com - Flying standby
