Hello @userbctcsales,

I appreciate you for reaching out to us about adding additional columns to invoices. Allow me to chime in and provide some clarification about the feature you need in QuickBooks Online.

Currently, the ability to add extra columns is unavailable. As a workaround, you can utilize the Description column to include additional details to each line item (see screenshot below).

Adding columns is also possible using the Desktop version. Users can go to the Additional Customization section of the template to include two more columns.

Though, it's a great feature that would benefit most QuickBooks Online users. While we assess this, I recommend sending your feedback directly to our product engineers.

They might consider adding this feature in the future updates. Here's how:

1. Click the Gear icon in the upper-right corner.
2. Select Feedback.
3. Add you feedback.
4. Hit Next to submit. 

Additionally, you can visit this article for additional guidance on how to personalize the format, as well as the data fields in QuickBooks: Customizing Invoices Within QuickBooks Online.

Please know that I'm just a post away if you have any other questions about the invoices or features in the Online version. Take care.