Create a subscription that bills per user

>is it possible for a company to buy subscriptions for individuals?

There are no billing schemes that allow that, as all store/IAP charges are tied to an individual user's Apple ID and iTunes account billing. See this link for details on iAP types from a user POV https://support.apple.com/en-us/HT202023

>confused on what Apple allows and does not allow for billing for content outside the App Store.

Have you read the ASRGs Section 3 Business / Payments? If so, do you have specific question?

It starts with what is being bought and how it's being used. Perhaps if you talked about process a bit, someone could help you understand the ASRGs, but I suspect that your business triangle (we;them;users) means all tracking, billing and related payments will have to be done outside the app and store.

You must use IAP if you are unlocking functionality in an app. What you want to do can be easily done with non-renewing subscriptions. The company can buy multiple subscriptions and transfer them to other users.

How does Amazon get away with this then? For instance you have to have an Amazon Prime membership to unlock functionality from their apps but you can't purchase that from the App Store.

Amazon prime is operating as a reader app.

They have other apps like Amazon Prime Video that can only be accessed by logging in with your Amazon account with a paid Prime subscription.

Can I do something similar where I just present the user with a login and they have to buy a subscription outside the App Store to access the app?

>and they have to buy a subscription outside the App Store to access the app

No.

From the ASRGs:

3.1.1 In-App Purchase:

If you want to unlock features or functionality within your app, (by way of example: subscriptions, in-game currencies, game levels, access to premium content, or unlocking a full version), you must use in-app purchase.

Another example is Twitch. You can buy subscriptions to different streamers to unlock content like emotes but these subscriptions cannot be purchased in the App Store.

Twitch on the App Store - iTunes - Apple

There seems to be many apps that conflict with rule 3.1.1. Can someone from Apple clarify?

You have two paths in front of you 1) complain about something you perceive to be unfair or 2) operate under the guidelines as they apply to you. Regarding the second path - all apps must function without requiring a log on unless there is a special circumstance. You don’t need to do much prior to requiring a log on. If you want to unlock code in the app you must use IAP. If all you want to do is display content you can operate as a reader app.

I'm not complaining I'm just trying to get clarification where the boundry is for purchases outside the App Store. There are clear exceptions like ebooks but it's not clear for other cases like Twitch.

Is there any documentation around this transfer process? Is this time consuming for instance if they bought a 1,000 subscriptions and had to transfer them to individual users.

The transfer system is all made up by you within your app. On device 1 you buy X subscriptions. Then on that device you debit X as you distribute subscriptions to other devices. Many ways of doing that. Generate a big random number (or a UUID or better, a CKRecordID); post that number to the public space in CloudKit along with corresponding subscription information; send that number from device 1 to anyone you want in an autogenerated email from device 1; when device 27 (for example) receives that email they delete the random number from CloudKit and they upgrade their subscription. ( A simpler system uses CKRecordID information and creates and deletes a CKRecord with that CKRecordID.)

It is important to explain to App Review that you are using this system to distribute IAP purchased subscriptions, not to give out coupons that get around IAP. It is equally important that App Review believes you.