If employers track employees' work time with time cards, some special precautions and policies are in order. Following are some things that employers may wish to consider:
require all employees to handle their own time cards;
prohibit employees from handling the time cards of other employees;
prohibit any changes or alterations to the time cards that are not pre-approved by designated supervisors;
prohibit employees from working "off the clock";
have employees sign their time cards;
include a certification on each time card to the effect that the time card accurately and completely reflects all time worked during the period in question and that no hours were worked that do not show up on the card.
For a sample policy that may help the company administer a reliable system for tracking hours worked, see the topic in this book titled "Work Schedules and Recording of Work Time".