Employee has left but i can't run his P45

I know it can be difficult when you can't issue a P45, Kirsten 1. I'm here to assist you with that. 

The P45 will show up when you mark your employee as a leaver before their last pay run. Since your employee was marked as a leaver after running their final pay, I'd suggest deleting the last pay run. Here's how: 

1. Go to the Employees or Payroll menu.
2. Select Payroll History and choose the most recent period.
3. On the Payroll details page, click Actions and select Delete Payroll.
4. Type YES in the box, then click Delete.
5. Repeat these steps for any additional pay runs that need deleting.

Then, you can marking your employee as a leaver. I'll show you how:

1. Go to the Employees or Payroll menu.
2. Select the name of the employee to open the profile.
3. Choose Actions and then select Mark as leaver under the employee name.
4. For the Details of leaving,
   • Add the employee's leaving date.
   • Enter the employee's reason for leaving.
   • Click Save.
5. Select Done to dismiss the note that their P45 will be available at the end of the final payroll.

For your visual reference, I'd suggest visiting this article: Mark Employee as a Leaver.

Once done, I'd suggest running a payroll again. Then, you can issue the P45 by going to the Documents on the individual Employee's profile page. You can also check out this article for more details: Employee P45 in QuickBooks Online Standard Payroll.

Additionally, I've included an article that'll help you stay informed about what to do when your employee leaves: One of your Employees Leaves or Retires.

I'll be right here to help if you need further assistance with the process, Kirsten 1. It's always my pleasure to help you out again.