Time Card. The least expensive option is a high-tech version of the old mechanical punch clock. Employees are issued a time card about the size of a credit card that they swipe on a machine similar to a credit card machine. While data is transferred automatically to produce computer-generated timesheets, thus eliminating all the manual paperwork, the one flaw is the same as the old punch clock: it allows for “buddy punching.” It's easy enough for someone to swipe a co-worker’s card who isn’t really there. According to the APA, buddy punching accounts for between two percent and five percent of payroll expenses. Proximity Cards, Badges , and Key Fobs. These eliminate the need for swiping. The employee only needs to pass the identifying card, badge, or fob in front of the reader, without actually having to insert it. In many cases, proximity cards track an employee’s movements throughout a facility—not just check-in and check-out. Biometric. These are pricey systems