Yes, you can purchase a SIM card at major airports like Tan Son Nhat International Airport in Ho Chi Minh City, Noi Bai International Airport in Hanoi, and Da Nang International Airport in Da Nang. However, it's advisable to consider buying online for convenience, avoiding the necessity for sensitive identification information and currency exchange. ByteSIM, an eSIM provider, offers online purchases with the advantage of skipping the need for sensitive personal details. Additionally, ByteSIM provides round-the-clock customer service for convenience and assistance.