Internal Revenue Code tax tips same way it treats any other income under the principle that all receipts are income unless clearly provided that an income is not taxable. Tips receipts by employee are taxable income under IRC . US tax law requires that employers in certain sectors like food and restaurant , bars, casino where it is custom to tip the employee to submit an annual report about the tips . From the information out of such report , IRS can compare the tips reported in the W2 to find out unreported tips . Therefore , it is legally important to tell the employer about the tips received by the employee. Please note that not only the tip receipt is taxable income , it is also subject to Social Security and Medicare tax withholding. So, every time one under reports , he/she also prevents unlawfully withholding tax on such income .