When adding an in-app purchase(IAP) to your app for the first time, be sure to follow the instructions provided by Apple closely. Make sure to dot your i’s and cross your… vision over the large warning at the top of the screen that says you must attach your first IAP to a new version of your app. This means it needs to be added after you create a new version in itunesconnect but _before_ you upload the binary for review.
I thought the pending status on my IAP meant it would just automatically be reviewed with my app during its next update. Wrong! On top of that screwing up your first IAP is not grounds for an expedited review so will have to wait another full review cycle to fix your broken IAP (which was only about 4 days in my case so not a huge issue). In the interim I just threw a bug warning into my app’s “What’s new” section that IAP didn’t work and a fix was on the way.
Here are some great articles from Apple that include step by step instructions on how to not mess your first IAP up like I did:
1. Adding In-App Purchase to your iOS and OS X Applications
2. Submitting your first in-app purchase product