Family Sharing subscription in iOS app

Implementing Family Sharing for Subscriptions in iOS App

Family Sharing for subscriptions — feature App Store supports since iOS 14. Essence: one family member buys subscription, others (up to 5 people) get access automatically. For app this means additional transaction verification and access rights logic.

StoreKit 2 and Family Sharing Check

In StoreKit 2 transaction contains ownershipType field: .purchased (bought self) or .familyShared (received via Family Sharing). App must check both when verifying access.

for await verificationResult in Transaction.currentEntitlements {
  switch verificationResult {
  case .verified(let transaction):
    if transaction.productID == "com.app.premium" {
      switch transaction.ownershipType {
      case .purchased:
        grantAccess(source: .directPurchase)
      case .familyShared:
        grantAccess(source: .familySharing)
      @unknown default:
        break
      }
    }
  case .unverified:
    // don't trust transaction — log, deny access
    break
  }
}

For subscription to support Family Sharing, enable in App Store Connect for specific product. Done once in In-App Purchase settings: toggle "Family Sharing" → "On for all members". Once enabled, can't disable for already purchased subscriptions.

Where Problems Appear

Revoke on family exit. If user leaves Family Group, .familyShared transaction gets revocationDate. Transaction.currentEntitlements stops returning it automatically. But if app caches subscription status locally (UserDefaults, Keychain) without checking actual state — user continues premium after revoke.

Correct approach: listen to Transaction.updates constantly, not just at startup:

func listenForTransactionUpdates() {
  Task {
    for await verificationResult in Transaction.updates {
      if case .verified(let transaction) = verificationResult {
        if transaction.revocationDate != nil {
          revokeAccess()
        } else {
          await transaction.finish()
          grantAccess()
        }
      }
    }
  }
}

Testing. In Xcode Sandbox can't fully test Family Sharing without multiple test Apple IDs configured as family in App Store Connect → Users and Access → Sandbox Testers. Create test family there via Family Sharing in Sandbox — mandatory step, without it .familyShared transaction check impossible.

StoreKit 1 vs StoreKit 2. In old API (SKPaymentTransaction) ownershipType unavailable directly. For checking family-shared in SK1 must validate receipt on server — field in_app[].is_in_family_sharing. StoreKit 2 migration significantly simplifies logic.

Work Included

• Family Sharing enable for products in App Store Connect
• ownershipType check via StoreKit 2
• Revoke handling on Family Group exit
• Persistent Transaction.updates listener throughout app lifetime
• Testing with Sandbox family
• Documentation for server side (if backend validation)

Timeline

3–5 days including App Store Connect setup and Sandbox account testing. Cost calculated individually.