Dear Koshikalulu,
Usually, every organization has a Leave Application form. If someone is willing to take a leave or has already taken leave, they should fill out the application and submit it to the HR Department with prior approval or immediately after availing the leave. This is a common practice.
You can send an Inter-Office Memo stating:
Leave Application Policy
This is to inform all employees of (company's name) that any Planned Leave should be approved before availing leave. If someone is on leave on a particular day, they are responsible for submitting the leave application with an approved signature from their Superior to the concerned department. Failure to submit the Leave application would result in a deduction from the salary for the day the employee was absent. We request all employees to strictly adhere to the policy.
HR Department
You may adjust the language or include any relevant details. The HR department has a responsibility to inform each employee individually about the eligibility of Leave.
Hope the above information is helpful.
Regards,
Meena