Cross-platform subscriptions: how to share entitlements between iOS and Android (without lying to users)

Original article (source): RevenueCat - “Cross-platform subscription state: sharing entitlements between Android and iOS” (Feb 24, 2026)

• https://www.revenuecat.com/blog/engineering/cross-platform-subscription/

The actual problem (it’s not a UI edge case)

Users expect: “I paid once, it works everywhere.”

Platforms deliver: two isolated billing universes.

• Google Play Billing can only see Google purchases.
• StoreKit can only see Apple purchases.
• Neither platform has built-in interoperability.

So if you don’t build a bridge, the Android app will happily show a paywall to someone who subscribed on iOS (and vice versa).

Why it’s genuinely hard

RevenueCat’s useful framing: the systems are different at a “philosophy” level, not just API shapes.

A few examples:

• Proof of purchase: Google gives you an opaque purchase token and you ask Google’s API for state. Apple gives you signed transactions (JWS) you verify.
• Real-time subscription events: Google uses Pub/Sub (RTDN). Apple pushes HTTPS notifications (ASN v2). Different plumbing, different payloads.
• Product modelling: Google’s base plans + offers don’t map cleanly onto Apple’s flatter “one product ID per duration” structure.

Translation: if you want one cross-platform “Premium” entitlement, you need a mapping layer and a state machine you can trust.

A pragmatic architecture (if you’re doing it yourself)

The post walks through the minimum viable building blocks:

1. Unified user identity (server-side) that both clients can associate purchases with.
2. Two verification paths (one per platform) with their own auth and parsing.
3. Unified entitlement storage that answers one question consistently: is this user entitled right now?

My editorial take

This is one of those problems that leaks straight into marketing:

• if your store copy implies “works on all your devices”, you’re making a promise your entitlement system must keep
• if support tickets spike around “charged twice”, your conversion rate and reviews take the hit

Tiny win: pick one entitlement (Premium), list every product ID/base plan that should map to it across iOS and Android, then write the exact rule your backend will use when the user logs in on a new device.

Read the original: https://www.revenuecat.com/blog/engineering/cross-platform-subscription/