Singapore Airlines operates at San Francisco International Airport (SFO) and provides customer service through a dedicated phone number for passengers. To contact Singapore Airlines at SFO, you can call their general U.S. customer service line at 1-800-742-3333. This number connects you to a representative who can assist with flight reservations, check-in, baggage inquiries, and other... https://askforairlines.com/singapore-airlines/singapore-airlines-san-francisco-international-airport-sfo-terminal/