From the main admin centre, you can head into the configuration section where you will find the settings to for your organisation

Once you are in the configuration section, you will see an option at the top for 'organisation details'

This is the section you will need to head into to add in a sub brand

When you are in the organisation details, head to the bottom of the page where you will see an option to add a sub brand

Click the add option

Once you have clicked the add option, it will bring up a screen where you can enter the details for the sub brand

Once you have applied the details, hit the save option.

It is worth noting that if you have created a sub brand, you will need to look at creating new templates with tags relating to the sub brand for this to show properly. Any tags which use the word 'sub' van be used

The guide on creating letters can be found here - https://guide.cloudcommercegroup.com/en/articles/5962942-ccp-templates-creating-a-template