Hi, @amandabadger. Let me share some information about changing a supplier to an employee.
The option to change the profile types from Supplier to Employee or vice versa is unavailable in QuickBooks Online (QBO). What we can do is create a new profile as an employee for that supplier. Make sure to add a special character to their name to avoid duplicates. I'll show you how.
Log into your QBO account.
Go to Payroll and select Employees.
Click the Add employee button and enter the supplier's information. Make sure to add a special character to the name just like in the sample below.
Click Add employee.
If you no longer need the vendor profile, you can make it inactive by following these steps:
Go to Get paid & pay/ Expenses.
Select Suppliers.
Select Make inactive in the dropdown menu from the Action column.