Hi Alexander, Thank you for your post. Here are the answers, 1. Yes, you can. In fact you should use the same SKU for live and sandbox to reduce the chance of error. You are supposed to test your IAPs in sandbox mode with the json file and sdkTester app before submission and in the json file you should define IAPs with the same data what you are giving in distribution portal for live. 2. You do not define or declare the IAP mode in the app. You implement the IAP with the classes given in IAP sdk and test it in json data. In the development build the IAP always works in sandbox. When you submit your app in the store, we test the IAPs in live. The build we generate from your submitted build for testing and putting that to live is enabled with IAP live mode. Hope I am clear.