A referral code is a unique alphanumeric code used to invite others to a service or app. When someone signs up using the code, both the referrer and the new user often receive rewards like discounts, cashback, or bonuses. Many companies, including fintech apps, e-commerce platforms, and travel services, use referral codes to attract new customers. These codes help businesses grow through word-of-mouth marketing while benefiting users. Popular examples include referral programs from PayPal, Uber, and Airbnb. To use a referral code, simply enter it during sign-up or checkout to unlock rewards. It’s an easy way to save money!