1. Radio buttons and dropdowns are used when there is a list of two or more options that are mutually exclusive and the user must select exactly one choice. As a rule of thumb, a dropdown would be used when there are more than five choices, otherwise radio buttons are used. The context of use may override this.
  2. Checkboxes are used when there are lists of options and the user may select any number of choices, including zero, one, or several.
  3. A stand-alone checkbox is used for a single option that the user can turn on or off. A checkbox is used for consent to terms and conditions.

Drop-down menus

Where there is a drop-down menu, the default should be that it is not pre-selected.

If it is decided in some cases that there should be a prompt, it would be e.g. ‘Choose your country…’, or ‘Choose payment card…’

Where the drop-down is defaulted to a selection, there must be a clear rationale for the choice e.g. in flight selling default ‘Country of departure’ to the customer’s home country, or ‘Class of travel’ to the most common selection.

Items should typically be listed according to a meaningful convention (e.g. alphabetically), although when the list is ‘long’, the most common items (e.g. UK, US) should be at the top,separated by dashes e.g

UK

US

- -

Afghanistan

Albania

The most common items should also appear in the correct position in the dropdown.

Drop-downs for navigation

Where a single drop-down is used for navigation it should immediately take the user to the new page, and should not require an additional click on a ‘go’ button.