The IRS recently released Revenue Ruling 2012-18, which provides updated guidance for employers on the treatment of employee tips for FICA-tax purposes.

Tips are subject to both the employer's and the employee's share of the FICA tax, even though they are not paid directly from the employer to the employee. Special procedures govern how employees report tips to employers and when employers must withhold and pay the required FICA taxes on those tips.

Among other things, the new guidance clarifies the distinction between tips and service charges. Service charges, such as automatic gratuities added to a bill for large parties, are not tips for FICA purposes and may not be reported using the special procedures that apply to tips. They must be treated like other wages paid by the employer. This means, for example, that they are subject to FICA-tax withholding at the time they are paid to the employee.

In a related announcement, the IRS has released a memorandum to field agents providing instruction on audits of businesses where tipping of employees is customary. The memorandum says that, in general, the principles in Revenue Ruling 2012-18 are retroactively effective. But in certain cases it may be appropriate for auditors to apply the new guidance on service charges prospectively from January 1, 2013, "in order to allow businesses not currently in compliance additional time to amend their business practices and make needed system changes."

Although this announcement indicates the possibility of some relief for employers that have not handled service charges in the manner required by the IRS, it also makes it clear that IRS agents will be actively auditing for tipped-employee issues.