If you produce a P45 for a leaver and notice that the tax code is blank, check if there's an 'effective from' date applied.

Correct the employee's tax code

1. Double-click the relevant employee.
2. Click the Employment tab.
3. Click the + button next to the Tax Code.
4. If the Effective From date is blank, select the tax code and click Edit.
5. Enter the date the tax code was effective from, then click OK.
6. Click Close, then Save.

You can now produce a new P45 with the tax code applied.