Using this guide you can disable the "Welcome" notifications that get sent out when a subscription has been provisioned.
Log in to 2tCloud with your reseller account and switch to Classic.
Go to the Billing side of the 2tCloud Service Automation
Within the Products section go to Service Plans
Open the subscription for which you want to disable the notification
On the bottom of the page click Edit
In the Notification About Service Provisioning field click the red cross (Cancel) or remove the text in the field.
On the bottom of the page click Save
You have removed the notification for this subscription