To delete a contact tag from your account (as opposed to removing a tag from a contact), start by navigating to your Settings menu. From here:

• Click on the Tags sub menu (1).
• Under Manage your tags here, use the Search bar (2) if required to locate the tag you wish to delete.
• Once located, click the X (3) next to the tag you would like to delete. *
• If the tag is not currently in use, it will be deleted instantly.
• If the tag is currently in use, you will see an alert advising where it's being utilised, for example in an Audience, Campaign, or Blacklist:
  • If the tag is not part of a Blacklist, you can choose to delete the tag, even if it is in use.
    Click Confirm to delete the tag.
  • If the tag is part of a Blacklist you will not be able to delete the tag.

* Tags that are a result of CRM integration, indicated by the Integrated icon (4), cannot be deleted here.
Delete these directly within your CRM.