iOS In-App Purchases

Developers can use Apple's StoreKit framework to incorporate in-app purchases (IAPs) into their apps on iOS, macOS, watchOS, and tvOS. The framework facilitates secure payment processing on behalf of the app, connecting with the AppStore and requesting user authorization for payments.

An In-app purchases SDK (Software Development Kit) is a set of tools, code libraries, and documentation provided by a developer platform, such as Apple or Google, that allows app developers to integrate the ability for users to make purchases within their app.

Server validation, also known as server-side receipt validation, is a process used to ensure that purchases made within an app are authentic. This is achieved by using an encrypted file, in PKCS#7 format, which contains information about all in-app purchases. To authenticate purchased content, you can include receipt validation code in your app or server. App Store receipt validation involves sending a request to Apple's servers to verify the purchase and determine whether it was valid. This is particularly important for auto-renewable subscriptions as you need to know when they expire in order to provide or block access to your content. Receipt validation is also used when users need to restore a purchase, such as when they reinstall your app.

A platform fee (commonly called the "Apple tax" or "Google tax") is the commission that app store platforms charge on in-app purchases and subscriptions processed through their billing systems. Apple charges 30% on most transactions through the App Store, reduced to 15% for developers earning less than $1 million annually through the App Store Small Business Program, and 15% on all subscription renewals after the first year. Google Play charges 15% on subscription revenue and 15% on the first $1 million of non-subscription revenue, with 30% above that threshold. These platform fees have a profound impact on the unit economics of subscription apps. On a $9.99/month subscription, Apple's 30% first-year commission means the developer nets only $6.99 — and $8.49 after the rate drops to 15% in year two. This fee structure has driven significant industry interest in alternative billing mechanisms, including web-based checkout flows that process payments outside the app store ecosystem. Regulatory actions worldwide — including the EU Digital Markets Act, Japan's TPSA guidelines, and court rulings in multiple jurisdictions — are gradually expanding developers' ability to offer alternative payment options and communicate pricing outside the app, creating opportunities for meaningful margin improvement.

In-app subscriptions are a payment model in which users are charged on a recurring basis in exchange for access to premium content, exclusive features, or services. They are frequently used by developers as a way to monetize their apps by providing users with ad-free experiences or exclusive content.