On the VATSIM network, filing a flight plan for VFR (Visual Flight Rules) is not strictly "mandatory" in the same way it is for IFR (Instrument Flight Rules) to receive a clearance, but it is highly recommended and considered "best practice." Filing a VFR flight plan provides Air Traffic Control (ATC) with essential high-fidelity information, such as your aircraft type, intended route, and altitude, which allows them to provide better flight following and traffic advisories. If you are flying in controlled airspace (like Class B, C, or D), having a plan already in the system makes the controller's job significantly easier when you "call up" for transitions or landings. In 2026, many VATSIM controllers prefer that all pilots file a plan regardless of flight rules to maintain the network's realism and efficiency. If you choose not to file, you must at least provide your aircraft type and intentions upon your first radio contact, but taking two minutes to submit a basic VFR plan ensures you are integrated into the "virtual" radar system more seamlessly.