How can we add units(Like Cartons, Pieces, boxes ect) in sales invoice or Supplier invoice .

I've got inputs to provide when managing units of measures for your product and service items, Ravitrader. 

Currently, the ability to add units for an item is unavailable in QuickBooks Online. However, as a workaround, the Product/Service information window in your account has a Description box that we can utilize to enter and specify the weights and units of an item.

Additionally, I recommend exploring our app market to look for third party providers that can provide this feature. You may also follow these steps in finding applications within your account:

1. Sign in to your QBO account.
2. Select Apps from the sidebar menu, then go to the Find Apps tab.
3. Enter a keyword in the search bar or click the Browse category button to filter the results.

Moreover, here are some references you can utilize to help you track inventories and reports in your account:

• Set up and track your inventory in QuickBooks Online
• Run reports in QuickBooks Online

I'll be around on this thread anytime you require additional assistance managing items in your company file. Just keep me posted in the comments below. Stay safe.

@ravitrader95-gma 

You need an inventory management app with UoM feature and integrate it with QBO.