Hi there, @frosted. Let's manage and deactivate your custom fields on the Custom fields page in QuickBooks Online (QBO).
When you create a custom field in QBO, even if it’s set up within a specific customer profile, it functions as a universal field tied to all customers using the same transaction type, such as estimates. Adding the field this way is simply an alternative to accessing the feature and doesn’t make it unique to that customer alone.
While it’s not possible to delete a custom field entirely, we can make it inactive for all customers, allowing you to reuse it later if needed. Here’s how to do this:
- Navigate to the Gear icon, then Custom fields.
- Click the Edit dropdown under your added field.
- Hit Make inactive.

You can also refer to this article for FAQs about this feature: Overview of Custom Fields Capabilities in QuickBooks.
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