Question

Does an In App Purchase’s Product ID have to begin with a Reverse-DNS like com.mycompany.My_Awesome_Game.Level_Pack_1 or can it just be standalone like Level_Pack_1?

Answer 1

Product IDs can be whatever you want, although it is recomend you follow the reverse domain name style. But in the end there’s no restriction over the naming of your product IDs. It also does not need to use your app bundle ID as a prefix.

From the source:

Q: I am implementing In App Purchase
and must register my product
identifiers. What are product
identifiers and how do I create and
use them in my application?

A: A product identifier is a string
used to uniquely identify every
product you wish to sell from your
application. The App Store uses it to
retrieve information about a product.
It is a string identifier that can
only contain alphanumeric
(A-Z,a-z,0-9), underscore (_), and
period (.) characters. You can use any
sequence of these characters for your
identifier. However, we recommend that
you use the reverse domain name style
(for example,
com.companyname.application.productid)
when creating your identifier.

So ‘Level_Pack_1’ —as in your example— would be a valid product id.