What are the differences between off-airport and on-site rental car companies at SeaTac Airport?

At Seattle-Tacoma International Airport (SeaTac), travelers can choose from various rental car companies, including budget and peer-to-peer agencies like Turo, Fox, and Sixt. However, not all companies are located within the main terminal facility. Off-airport rental car companies, such as Enterprise and National, operate from nearby locations and require shuttle transfers to and from the airport. The shuttle service typically takes around 10-15 minutes, depending on traffic. In contrast, on-site companies like Alamo, Avis, and Hertz are situated directly within the Rental Car Facility, which is connected to the main terminal via a shuttle bus or walkway. The Rental Car Facility is located at 18200 International Blvd, SeaTac, WA 98188. Some off-airport companies may charge additional fees for shuttle services, while others may offer complimentary transportation. For example, Turo's shuttle service costs around $5-$10 per person, each way. It's essential to check with your chosen rental car company for their specific shuttle schedule and fees to plan your trip accordingly. On-site companies, on the other hand, offer the convenience of being directly accessible from the main terminal, with no additional shuttle transfers required. The Rental Car Facility is open 24/7, and the shuttle bus operates every 15-20 minutes.