Sandbox vs Live/Production.
Users - Team Members
Live accounts and Sandbox accounts have a Parent to Child relationship. Any Team Member in the Live account will have access to the associated Sandbox account with the same permissions. Any Team Member in the Sandbox Account will not have access to the associated Live account. In addition, Team Member emails must be unique across all Payment Rails merchant accounts (both Sandbox and Live). If a team member is added to the Sandbox account, you will not be able to add them to the Live account unless you delete that team member from Sandbox, or use a different email address when adding them.
If you have added recipients on your Sandbox you need to delete them from Sandbox first and add them to the Live account or if you are using the widget you're going to have to ask the recipients to enter their details after you switch to live API keys.
The Sandbox system has 100% of the functionality of the Production system. There are clear areas where there are differences, we don’t send real bank payments, However, all the steps and components are the same.