Guideline 3.1.1 - In-App Purchase: License Key or Serial Number Unlocks

Apple is rejecting your app because it uses license keys, serial numbers, or activation codes purchased outside the App Store to unlock functionality within the app. This is a variation of the external payment bypass -- the purchase happens elsewhere (your website, a physical retailer, a B2B agreement), and a code entered in the app unlocks premium features. This pattern is extremely common in enterprise and B2B apps, productivity tools with desktop counterparts, and apps that originated on other platforms. The developer often assumes that because the sale happened externally, it falls outside Apple's IAP requirements. It does not -- if the key unlocks digital content or functionality consumed within the iOS app, IAP is required. The exception is if your app qualifies as a reader app (3.1.3(a)) or if the license was purchased as part of a multiplatform service where the iOS app is one of several consumption points. Even then, you cannot include a license entry field in the app itself -- the entitlement must be tied to account-level authentication.