Billing entities separate who pays from who uses the product. Designate a company as a billing entity and it pays the subscriptions of every company associated with it, on one combined invoice, with one payment method. The associated companies keep their own plans, entitlements, usage, and limits, and manage their own plan. Only the billing entity is a customer in your billing provider, so the accounts consuming the product do not each need a card on file.

This handles the cases where the buyer and the user are not the same account: a parent company paying for its subsidiaries, or an agency buying on behalf of its clients. Assign a billing entity through the company upsert, provision parent and child accounts together, and import existing multi-subscription Stripe customers with the association preserved.