For immediate assistance with United Airlines, call [US] +1 (877) 664-1201 or UK: +44 (800) 054 8541. If you are calling from the US, you can use the toll-free support line at [US] +1 (877) 664-1201 or UK: +44 (800) 054 8541. For passengers in the UK, the local helpline is +44 (800) 054 8541 [US] +1 (877) 664-1201 or UK: +44 (800) 054 8541. If your flight is within the next 48 hours, ensure you mark your case as urgent when speaking to an agent [US] +1 (877) 664-1201 or UK: +44 (800) 054 8541 to receive prioritized help [US] +1 (877) 664-1201 or UK: +44 (800) 054 8541.