Fix: "Your app must use a newer version of the Google Play Billing Library" (Billing Library 7/8)

What triggers it, the official deadline, and the fix by stack. Sources checked 2026-10-02.

Fix by stack

Flutter

Update the official in_app_purchase plugin to a version whose changelog names Billing Library 8 (or whichever third-party IAP plugin you use) — the Dart API doesn’t change, only the native dependency it pulls in.

React Native / Expo

There’s no first-party Google wrapper for RN; most apps depend on a community package such as react-native-iap. Update it to a release built on Billing Library 8 and rebuild — check the package’s own changelog, since the RN/Expo wrapper version doesn’t track the Billing Library version number.

Unity

Unity IAP rewrote its API in the 5.x line specifically to move off the deprecated Billing Library versions; see Unity’s own support article and Google’s Play Billing for Unity doc. Upgrading from IAP 4.x to 5.x requires redoing the purchase code; the API was not kept compatible.

Not sure which of these applies to you? All four Google Play native-code deadlines are on one page, and the free dependency checker or check16k.py will tell you if 16 KB alignment specifically is your problem.