Glad to have you here, @lisaalvarez1981.
I understand how important it is for you to use the right credentials to create your QBO payroll login account. Let me help you clear things up.
Your login account in QuickBooks Self-Employed (QBSE) can also be used in creating your payroll account, as long as it's the same QuickBooks products. The data won't mix up, and whenever you sign up, you will be prompted by options of what account you'll log in to.
For more info, you can read this article: Use one user ID to access multiple companies in QuickBooks Online.
On the other hand, you can also use another email as your login credential for your payroll account.
If you want to learn how to manage multiple company files, check out this article: Create or add another company file to QuickBooks Online.
Never hesitate to come back here if you have more questions about login credentials in your QBO payroll account. I'll be willing to lend a hand. Have a good one.
