Connect with and learn from others in the QuickBooks Community.
Look no further! I can help you find and update your category list quick as a wink, @matthew27.
Can you clarify which categories you are referring to? This might apply to Ledger Accounts, Classes, Product/Service categories, etc. Anyway, you can access all your lists on the All Lists page.
If you're referring to the categories available to select for bank transactions (i.e. Ledger Accounts), check out this link: Add to or edit the Chart of Accounts.
Also, here are some helpful resources you can use in organizing your lists in QuickBooks Online:
Please touch base with me here if there's anything else I can do to help you out. Thanks for coming to the Community and take care.