I would like to add fields in the Products & Services module

Hi there, Nick. To add multiple categories/sub-categories, navigate to the Manage Categories section.

Please note that adding UDF fields in Products and Services is unavailable in QuickBooks Online (QBO).

To create categories and sub-categories, follow these steps:

1. Head to the Gear icon in the upper right of your screen. 
2. Choose Products and services under Lists. 
3. Navigate to the More dropdown. 
4. Select Manage categories. 
   
5. Click Create New Category. If you want to add sub-categories, check the This category is a sub-category box.

To manage your categories, view this material: How to use and manage product categories.

If you'd like categories to show on customer forms, you can customise your sales forms.

Feel free to leave a comment below if you have additional questions.