Can the same contact be supplier and customer both?

Hello humna-salman-gma,

Great to see you here in the Community. Yes, we can add the same contact as both your supplier and customer in QuickBooks Online (QBO). 

Though, we need to make one unique from the other so QBO won't recognize it as duplicate name. 

I often add details on the Title field in the Customer information page. This makes it different from the name I saved as the supplier. Here's how: 

1. On the left panel, click Sales.
2. Choose Customers Tab.
3.  Select New Customer. 
   
4. Add prefix on the Title field. You can also use the Suffix field or choose to opt out the Middle name field. 
5. Once all necessary info are filled in, hit Save. 
   

Then add your supplier. You can also check out this article about moving your lists to QuickBooks Online. 

Now you can start managing customers and suppliers transactions. See these articles for more details: 

• Customers
• Suppliers

You can always find me here if you have any other concerns or further questions about QuickBooks. Have a great rest of the day.