Good day, @userinfo.jeferenterp.
Thanks for reaching out to the Community. I'm here to share information about managing invoices in QuickBooks Online (QBO).
The option to create additional columns on invoices is unavailable in QBO.
I can see how this option would be helpful for you and your business. I suggest sending feedback to our product developers. That way, they can review your request and most likely include it in our future updates. Here's how:
Moreover, you can create a new template to personalise and add specific info to your sales forms. This feature will help customise the appearance and layout of your invoices. That way, you can enhance your business' communications.
I also recommend visiting our website for tips and other resources: QBO self-help articles.
If you have more questions about invoices or anything else QuickBooks, please let me know in the comments. I'll be here to answer them. Keep safe.