Hi @wake92,

Yes, you definitely can. 

Be advised, each name entry should be unique in QBO. With that said, you can enter a company name as is when you record them as a customer. Then make a slight change in their name when you record them as a vendor. This way, you'll recognize that both are the same company. It's only that one entry is a customer, while the other is a vendor. 

If you're in a situation where you need to record an exchange of goods between your vendor which is also a customer, you can refer to this article: Record a barter transaction. 

Utilize the comments section below if you have other questions about managing your customers and vendors in QBO. I'll take care of them for you.