Answer: Eric, SPHR, SHRM-SCP, one of our HR Pros says…
It is not a requirement that timesheets be signed. We recommend that employees acknowledge that their time records are accurate, either by signing them or by some other submission and acknowledgment method or technology. Having employees review and approve their timesheets prior to submission allows for prompt correction of errors and reduces the likelihood of unreported hours. Signing is an easy and a common way for employees to affirm the accuracy of their recorded hours.
If an employee fails to sign their timesheet, you should not withhold their pay, as it is fundamentally the responsibility of employers to track and pay for hours worked. If an employee performs work but fails to turn in a timesheet, you should make your best estimate as to hours worked based on all information available to you. If you discover changes are needed, you should make the correction as soon as possible.