Up to 10 stores per account

Changed for merchants

• 10 stores per account. Every store that has not been removed counts, whether it is published or not. Removed stores and partner development stores don't. At 10, Settings → Stores shows "10 of 10 stores" and replaces Add store with Contact us. The store switcher's Add Store opens the same explanation instead of a form. See Up to 10 stores per account.
• New error for the API. Creating an 11th store answers 409 STORE_CAP_REACHED with "You can have up to 10 stores. Contact us to remove one you don't use, or to get more." and errors: { limit, count }. GET /settings/stores/limits now also returns account_limit and reason.
• Contact us for more. We can raise the limit for one account, or remove a store you no longer use.

Kept working

• Accounts that already have more than 10 stores keep all of them. Nothing is removed or paused, and every store keeps working. Those accounts can't add a store until they are under 10.
• Per-store plans, the one-unpaid-store rule and development stores (up to 20 per partner organization) are unchanged.