If you have already purchased licenses for your existing Office 365 tenant through 21st Webb, you can simply order more licenses from the Services page, and these will be linked to the same Office 365 tenant as before, as it will already be linked to your 21st Webb account.
If you have not ordered any licenses through 21st Webb before, please click on the link below for information on creating an account with 21st Webb and linking your existing Office 365 tenant to it:
Click here for help on linking your existing Office 365 tenant
Once you have followed the steps linked to above, we will confirm with you when your Office 365 tenant has been linked to your 21st Webb account. As soon as this has been confirmed, you can login to your 21st Webb account, and order new licenses from the Services page.