I've got the information you need, Abdul Rehman.

Adding a payee on the expense allows you to keep track of how much you spend with each supplier over a period of time. But, as long as you have selected the correct account, your financial reports will not be affected. 

If you've like to have a detailed information in your business reports, it would be best to add a payee. Here's an article on how to view all transactions for a supplier. 

I'm here if you have any clarifications about the use of suppliers in QuickBooks. Thanks.