When your Recurly site is in sandbox or development mode, you can use the Clear Test Data button within the Site Settings configuration page to delete all customer data that currently exists on your site. This would include customer accounts (and related subscriptions and transactions) that were created in your test site. This action will not impact any configuration elements such as subscription plans, coupons, or email templates. All third party integrations, such as Xero and QuickBooks Online, will be removed when test data is cleared. This action is not reversible, so use it with caution.