App rejected due to 3.1.1 - Business - Payments - In-App Purchase

RomOne's answer helped us getting our app approved into the appstore. In our case the appeal board concluded with:

*App Store Review Guideline 3.1.1, while the app is free to download, users have to make payment for ****** service. Apps that operate across multiple platforms may allow users to access content, subscriptions, or features they have acquired elsewhere, provided those items are also available as in-app purchases within the app.*

After explaining to B2B usage of the app, where companies need to have a subscription and not the employees/users of the app, and stating that this in-app purchase feature would never be used by these users, we finally got our app back in the appstore.

In your communication with Apple you can point to the following clauses of the App Store Review Guidelines (https://developer.apple.com/app-store/review/guidelines/), if applicable (it was applicable in my case):

3.1.3 Other Purchase Methods: The following apps may use purchase methods other than in-app purchase. Apps in this section cannot, within the app, encourage users to use a purchasing method other than in-app purchase. Developers can send communications outside of the app to their user base about purchasing methods other than in-app purchase.

3.1.3(c) Enterprise Services: If your app is only sold directly by you to organizations or groups for their employees or students (for example professional databases and classroom management tools), you may allow enterprise users to access previously-purchased content or subscriptions. Consumer, single user, or family sales must use in-app purchase.

3.1.3(f) Free Stand-alone Apps: Free apps acting as a stand-alone companion to a paid web based tool (eg. VOIP, Cloud Storage, Email Services, Web Hosting) do not need to use in-app purchase, provided there is no purchasing inside the app, or calls to action for purchase outside of the app.

You will need to go in the resolution centre and explain them in detail your issue. My previous company used to have a B2B app with a company based subscription outside the AppStore. To pass Apple verifications, we had to discuss that with them in details and highlight the fact your app is a B2B one.

Here is an interesting post: https://www.designernews.co/stories/9695-how-do-apps-like-lyft-uber-airbnb-skirt-apples-30-cut-on-each-transaction