How do i add a back order column to a packing list on the on line version of QB

I'm glad you ask about this, mark68.

At this time, adding a back order column for packing list is unavailable in QuickBooks Online (QBO). 

We're looking for ways that would improve this feature and the ability to customize the packaging form is one thing to consider. It uses a default format set by QBO. Our developers always made sure to study the benefits of the new features before they release it.

To stay updated with the latest QuickBooks news and updates, I encourage you to visit our QuickBooks blog.

The Community is always open if you have other questions. I'll be around to help. Wishing you a great day ahead!