Your eCard details are visible on documents you send to your clients.
Your eCard can be changed via Settings > Style & Branding.
Click on the "eCard" tab at the top left.
From here you can go through and edit your details.
The eCard tab contains publicly visible contact details. These details can be displayed via Client Connect, your invoices, reports (refer to examples below) and any emails sent out to your clients.
As an example, clients who log in to Client Connect will be able to see your eCard as follows:
PDFs you generate may look like the following: