There is no prescribed template for such Memo/warning letters. You need to prepare Memo based on the situation.
Is your employee is not mentioning the In & Out in the Attendance Register or not using Biometric access ? In either case call the employee and explain how in-out timing are very important for HR to process salary. Indicate to him that if he/she forget to mark the attendance in the future those days will be considered as loss of pay or need to get certificate from his Reporting Authority confirming his/her presence to work on that particular date.
If your employee continue to miss the attendance even after verbal warning then you may go for warning letter or memo..
If you are using biometric access there are provisions like the entry door will open only if the employees uses the id card/ thumb impression in the bio-metric access. Such system in place will help arrest these sort of complaints.
From India, Madras
aussiejohnIt is surely not beyond your ability to write a simple memo to all staff stating that everyone must record their time of arrival and time of departure. You can fill in the details of how that is done in your organisation, i.e, time clock, sign in book, online register, whatever method you use.
In addition to that, you MUST outline the penalties for failure to record attendance, e.g. loss of pay etc, etc.
Any recalcitrant employees can then be dealt with via warning letters as my colleague above has outlined.
Your life will be much easier if you don't overcomplicate simple processes, and keeping things simple means that employees understand more easily what is required of them.
From Australia, Melbourne