Why are students NOT able to claim exemption on their W-4 form?

Students are generally not able to claim exemption on their W-4 form because they typically do not meet the income threshold required to qualify for the exemption. To claim exemption, a taxpayer must have had no tax liability in the previous year and expect none in the current year. Most students earn income that may be subject to withholding, thus making them ineligible for exemption. Additionally, claiming exemption incorrectly can result in tax liabilities at the end of the year.