I'm here to assist you in changing a vendor to a Customer, mitchsequip.

Changing the vendor to a customer is super easy. And I can guide you with the detailed steps to change the vendor to a customer. Here are the steps you need to follow:

First, we make sure to make the Vendor Inactive:

1. Click Expenses and choose Vendors.
2. Select the vendor's name, under Action, click the dropdown, then choose Make Inactive.

Once done, set up a new Customer name (QuickBooks Online doesn't allow duplicate names). 

1. Click the Customers & leads and select Customers.
2. Select New Customer at the top right.
3. In the Last Name field, choose a name one keystroke different from the Vendor name (such as John J. Doe, if the Vendor name was John Doe, for example).
4. Enter the rest of the contact information.
5. Tap Save.

It's important to note that when you convert a vendor to a customer, the vendor's open bills will not be converted to invoices automatically. You will need to create new invoices for the converted vendor manually.  

You can open these articles for more information about adding customers:

• Add and Manage Customers in QuickBooks Online
• Moving Names from One List to Another

Do you also need more references about managing vendors in QBO. If so, feel free to check out these articles:

• How to Manage Your Vendors List
• View Vendor Transactions

As always, please feel free to revisit us and ask any questions you may have. We are always here to help and address all your concerns. Have a great day!