What is an offer code (promo code)?

On the App Store there are three types: one-time-use codes, custom codes such as SPRINGPROMO, and sandbox codes for testing. You can have up to 10 active offers at a time and up to 1,000,000 codes per app per quarter. For subscriptions you choose who may use the code: new subscribers, existing subscribers or expired subscribers in the group. One-time-use codes come in batches of 500 to 25,000 and are valid for at most six months. Subscriptions support offer codes from iOS 14.2, and other product types from iOS 16.3.

When someone redeems a code, your app receives a normal transaction. Your server receives OFFER_REDEEMED for an active subscriber, SUBSCRIBED for a first purchase or resubscribe, or ONE_TIME_CHARGE for a one-time product. The transaction's offer type is 3 for an offer code.

Google Play promo codes cover paid apps, one-time products and subscriptions. One-time-use codes can be redeemed in Google Play or in the app. Custom codes work only in the app, only for subscriptions, and only for people who never subscribed before. A subscription promo code gives a free trial of 3 to 90 days. RevenueDot records an App Store offer code with the type offer_code and sends its identifier as offer_code in webhooks.

Sources: Apple: Supporting offer codes in your app · App Store Connect Help: Set up offer codes · Apple: Auto-renewable subscriptions · Play Console Help: Create promotions