Terms of use

Last updated November 12, 2026.

What Box12TT is

Box12TT is a calculation aid. It applies the Fair Labor Standards Act regular-rate method to the data you provide to estimate qualified overtime compensation for Form W-2, box 12, code TT. It is not tax, legal or accounting advice, and it does not file anything with the IRS or the Social Security Administration.

Your responsibility

Results depend entirely on the accuracy and completeness of your data, including correct workweek hours and earnings classifications. You are responsible for reviewing results, especially weeks the calculator flags, and for the information returns you file.

Season pass

The 2026 W-2 Season Pass is a one-time purchase that unlocks unlimited employees, exports and the audit trail until April 30, 2027. It is for use by the purchasing firm or employer and its staff. If it doesn't fit your data, ask for a refund within 14 days of purchase.

Limitation of liability

The software is provided as is. To the extent the law allows, our total liability for any claim is limited to the amount you paid for the season pass, and we are not liable for penalties, interest or indirect losses.

Changes

We may update the calculator as IRS and Department of Labor guidance changes. Material changes to these terms will be posted on this page.