Why does my ex employees p45 say he’s earned nothing

It's possible that we had changes to the employee's information, heatstyleplumb. 

We can look into the Audit Log report if there were changes made. 

1. Just go to the Gear icon and click Audit log.
2. Use the fields on the Filter panel to choose the appropriate User, Date, or Events filter to narrow the results.
3. Select Apply.

I also suggest that we view the pay calendar to ensure that they correspond with the leaving date of the employee. The pay period dates of the last period may not match with the date of the leaver. Here are also a few article that will help us identify when to report P45:

• What to do when an employee leaves
• PAYE form

Get back to me if you nee more help. Always stay safe!