In Australia, every state or territory requires by law any umpire/referee over the age of 18 to have a Working With Children Card.
Ideally we would want the system to recognise when someone is turning 18 and give them reminders in the lead up to turning 18 that they will need a WWC.
Also, if they are over 18 and have not submitted a WWC then the system should tell them, and also make them unable to operate or be assigned to games.
If their WWC expires it should do the same thing also.

I know in southern Australia that we have a referee manager program that has been developed by a basketball referee and that currently operates at around 15 associations and includes the Victorian, South Australian and SEABL semi-professional basketball leagues. If you could include this feature, I am very sure that other associations would very quickly move to your program as the current system is clunky, IT support is poor but has WWC and better ability to insert assessment information.