Thank you for sharing your input @glennedy1. As others have mentioned above, if you give either the customer or supplier version of this company a slightly different name, you'll be able to enter it as both. I hear what you're saying though, and I know that having one profile act as both a customer and a supplier would be handy. Our product development team works on implementing additions like this into QuickBooks Online in order to ensure that we meet our user's needs. Let them know how adding a company as a dual Supplier and Customer would be beneficial by navigating to the Gear icon, then selecting Feedback.
