Let's make sure you'll be able to set up custom fields in your invoice, userbeyondgarage-fin.
You can create your own custom fields in QuickBooks Online (QBO). To do this, I've outlined the steps below:
Once done, all custom fields created will appear on the list so you can manage them quickly. Here's how:
For more information, go through this article for your guide: How to add custom fields to sales forms and purchase orders. Apart from this, to give you accurate information about your business, you can run reports and customise them. I've included this article for you: Customise Reports In QuickBooks Online.
Reach out to us if you need anything else with custom fields or if you're referring to something else. The Community is always here to make sure you'll get covered.