Why do I have to create an account for each company I do payroll for?

Thanks for reaching out, corporateplus. I'm here to lend a hand about creating an account for payroll for each company.

QuickBooks Desktop Payroll can only support one company file per EIN. This is to avoid causing errors when attempting to use multiple company files under the same EIN. You can check out add an EIN to existing Payroll Subscription that contains the requirements and limitations about this.

Here are managing payroll-related articles for additional guide and reference:

• Managing payroll subscriptions for multiple companies
• Resolve a problem verifying your payroll subscription

Please add a comment below if there's anything else I can do to help you with it. I'd be glad to assist.

You don't.  You can include up to three company files when using Basic or Enhanced payroll, or up to 50 when using the Enhanced for Accountants subscription.

You can add EINs to your subscription, but you will need separate actual QB files for each EIN.  So yes, that means you will have a one QB file for each company.