Welcome to the Community, @Matt1997.

Currently, the option to add more columns to an invoice is unavailable in QuickBooks Online (QBO). This is because the columns on the invoices page are predefined, which has only given you the option to hide or display the columns in the Custom form styles page.

However, you can utilize the Custom fields feature to add more details to your invoices. Here's how:

1. Click the Gear icon and select All lists.
2. Select the Custom Fields.
3. Click the Add field, then enter a name to the newly added field.
4. Hit Save.
   

I recognize the significance of having the option to add extra columns to an invoice. You can then send feedback directly to our Product Development team so they may consider including this feature in future updates. To do that, here's how:

1. Go to the Gear icon at the top.
2. Select Feedback.
3. Enter your comments or product suggestions.
4. Click on Next to submit feedback.

Our Product Development team will receive and review your suggestion along with the other user's requests.

You can also track feature requests through this link: QuickBooks Online Feature Requests.

In addition, let me share these articles with you for additional reference: 

• Import Custom Form Styles For Invoices Or Estimates
• Customize Invoices, Estimates, And Sales Receipts In QuickBooks Online

You have my attention in case you have additional questions about managing your invoices in QBO. Keeping you in working order is my top priority.