Icons are used to make the site more engaging. They're limited to use on the home page only to reduce and performance issues.
There are exceptions to this rule as they can used in specific components to improve their usability. For example, the search button in the header uses a magnifying glass and the social media links in the footer use the relevant icon for each app.
We use the free tier of Font Awesome icons.
We need to make sure that all icons meet WCAG 2.1 colour contrast guidelines.
You can find out more about our colour palette and how to use it on our colours page.