The types of benefits typically reported on a P11D include:
In Moneysoft - Click Employees - then click Employee Benefits. You can then select the employee and manually add the total benefits they get for the year. You only submit the P11D at the end of each tax year. The deadline is 6th July each year for the year previous.
To correct a P11D for prior years - you can attempt at the link below (online) to correct a P11D.
https://www.gov.uk/employer-reporting-expenses-benefits/reporting-and-paying