Hey @Jaspreet_Singh - thanks for confirming.
The confirmation page is specifically designed to display the recurring plan price (what you’ll be billed per cycle going forward), not the prorated charge for the current period. The replacementBehavior value only changes the description wording on that page (whether it says your new plan “immediately replaces” the previous one or replaces it “once your current app subscription billing cycle is complete”). It doesn’t affect the price shown.
The prorated amount for the current period gets calculated and applied at the time of acceptance, based on the formula from my earlier reply.
There’s a similar thread from a little while back where my colleague Kyle covered this: Inconsistent Behavior for replacementBehavior=APPLY_ON_NEXT_BILLING_CYCLE in appSubscriptionCreate Mutation. Not exactly the same scenario, but the underlying logic is the same: replacement behavior governs billing timing, not what’s displayed on the confirmation screen.
If you want to verify end-to-end, you can check the actual charge on the test sub’s transaction record after accepting. You should see the prorated amount there, not the full plan price that was shown on the confirmation screen.
Let me know if I can clarify anything further on our end here!