Definition
What a subscription group is
In App Store Connect, every auto-renewable subscription belongs to a subscription group. Apple describes a group as subscriptions "with different access levels, prices, and durations" that people can choose from. A typical app has one group with a monthly and a yearly plan, or a basic and a premium level.
Apple allows up to 100 subscriptions per group, and someone can only hold one active subscription per group at a time. Inside the group they can upgrade, downgrade or crossgrade as often as they like.
Why it matters for offers
The group decides who can use your introductory offer. Apple says customers can redeem one introductory offer per subscription group. So if someone used the free trial on your monthly plan, they can't get the trial on your yearly plan in the same group. The App Store tells them they aren't eligible for the introductory price but can still subscribe without it.
Win-back offers also follow the group: a customer is only eligible for the win-back offer of their most recently lapsed subscription in each group.
Why it matters for revenue
Your proceeds go from 70% to 85% after a subscriber has one year of paid service in the same subscription group. Moving between plans in that group doesn't reset it. Moving to a different group does. (Members of the App Store Small Business Program get 85% from the start.)
One group or several?
Apple recommends one group for most apps, and a second group only when people should be able to buy two subscriptions at the same time. App Store Connect shows a warning when you create the second group.
Examples
A habit tracker with one group
A habit tracker sells $9.99 a month and $59.99 a year, both in one group. Someone takes the 1 week free trial on the monthly plan, then switches to yearly. They don't get a second trial, and their year of paid service keeps counting toward the 85% rate. These prices are illustrative.
Frequently asked
Why does the App Store say I'm not eligible for the introductory price?
Apple allows one introductory offer per person per subscription group. If you already used a free trial or intro price on any plan in that group, the App Store lets you subscribe at the regular price only.
How many subscriptions can a subscription group have?
Up to 100. A customer can only have one of them active at a time.
Should my app have more than one subscription group?
Usually not. Apple suggests a second group only when customers should be able to hold two subscriptions at once, because each group has its own active subscription and its own year of paid service.