Navigate to Admin > Templates and select Quote Templates, Invoice Templates, Supplier Invoice Templates and Order Templates.
Click on each to create header templates, footer templates, cover page templates, and terms & conditions page templates, the steps are the same for each.
Editing the Header, Footer and Creating a Cover Page and Terms & Condition page is located in the same place for Quotes, Invoices, Supplier Invoices and Orders and can be located as per below:
Create Templates for your Quotes Headers and Footers and Quote Cover pages and Terms & Conditions pages. Click to add a new template for each. This example shows you how to add a Quote Header Template. First select Add as shown below:
Edit your Templates name, Add content to your header template. You can copy and paste text here, type what you want in the header and Insert Merge Fields.
Your new template will show in the Header Templates list. You can Set a Template as the Default, this will then create that header for every Quote you create.
To add your Header template to a Quote you will need to go into the Quote, Click to edit the header notes and select a Template from your list and Save. You can preview the header to see Merge Fields.