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Under normal conditions when customer registers on frontend the current shop is automatically assigned to their newly created account. If "Require Approval" feature is configured in shop for specific customer type (say business user want to approve all B2B customer registrations), then the shop assigned is created and set to disabled mode straight away, which also trigger notification to shop administrator that an account needs activation. Shop administrator can then review the customer account and click the green enable button to activate the account.
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