If you find yourself unable to select a seat with United Airlines, there are several steps you can take to address the situation.

First, ensure that you are logged into your United account and that you are viewing the correct flight details. Sometimes, seat selection may not be available due to the fare type you purchased, as basic economy tickets often do not allow for advance United Airlines seat selection. 

If this is the case, you can wait until online check-in opens, typically 24 hours before the flight, to choose your United Airlines seat. 

Alternatively, you can contact United Airlines customer service for assistance at +1(855)-838-5939; they can help clarify why seat selection is unavailable and may be able to manually assign you a seat or provide options. 

If you’re at the airport, you can also visit the United check-in counter or the self-service kiosks to select a seat. Remember to check for any available upgrades that might offer better seating options. 

Lastly, if you’re traveling with companions, inform the staff at check-in about your group; they may be able to help seat you together.

Hopefully, you get all details about United Airlines Seat Selection map and policy here and "What to Do If You Can’t Select a Seat With United Airlines?". If you have any questions then visit official United Airlines webportal or call at +1(855)-838-5939.

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