The Emerald Club is a loyalty program offered by National Car Rental that rewards frequent renters with various benefits. Members can enjoy perks such as expedited service, free upgrades, and the ability to choose their own vehicle from a designated area. The program is designed to enhance the rental experience for those who rent cars often. Joining the Emerald Club is free and can be done online. Members earn points for each rental, which can be redeemed for free rental days or other rewards. The program also offers different tiers, allowing members to unlock additional benefits as they rent more frequently.