How do i add si# after i terminated an employee due to lack of work, now I want to bring him back but system will not allow me to add his si# because it's a duplicate?

Hi there, 

Welcome to the Community. QuickBooks makes it simple to make an employee active again. I'll be happy to steer you in the right direction so you can get back to doing what you love the most. 

In order to make changes on the employee in question you'll first have to make the employee active again. Here's how:

1. Select the Payroll and navigate the employees screen.
2. Select Include inactive.
3. Click on the employee in question and select Make active.

 Here's an article with more helpful info: Add, edit, or inactivate an employee. 

Give this a try and if you have further questions, I recommend contacting our support team using this link.