From AT&T Support Wiki
Settings > Administration > Company Information
Users that have the Manage Company Capabilities permission can modify the company logo.
- A logo image that is 400px wide by 40px tall.
To add a company logo:
- Click Settings > Administration > Company Information
- Click the [Edit] button
- If it is not already present, click the link to upload the image to the Documents library.
- Click the Lookup icon to select the image from the Documents library, or start typing into the field to take advantage of the Auto-Completion capability for Lookup fields.
- Select the image.
- Click [Save]
- The logo image appears in the platform banner.