iPhone StoreKit - invalid product id's

I'm trying to test In App Purchase within the sandbox environment. In order to test the code I did the following: Created an In App Purchase Test User account under 'Manage Users' in iTunes Connect Created some in app purchase products under 'Manage Your In App Purchases'. I used numeric values and alpha-numeric values for the Product IDs. Loaded the app onto the iPhone, went to Settings->Store and logged out of the regular store and into the test account created in step 1 Set a breakpoint in the (`void)productsRequest:(SKProductsRequest *)request didReceiveResponse:(SKProductsResponse *)response` callback All the submitted Product ID's are in the `response.invalidProductIdentifiers` property. When submitting the request I first tried the exact Product IDs created during step 2. I also tried prefixing them with the Bundle ID: ``` NSString *id2 = @"com.super.duper.8"; NSSet *productList = [NSSet setWithObjects:id2, @"8", nil]; SKProductsRequest *request= [[SKProductsRequest alloc] initWithProductIdentifiers:productList]; ``` Am I missing something obvious? Any help is appreciated. Achim