Tie-out tool / Correct Code TT on Form W-2c

How to correct Code TT on Form W-2c

File Form W-2c with a Form W-3c. In box 12, enter code TT with the original amount under Previously reported and code TT with the right amount under Correct information.

Worked example

An employee was paid $1,500 of overtime at time-and-a-half, every hour worked over 40. The payroll export put the whole $1,500 in box 12 with code TT. The right figure is the half-time premium: $500.

Form W-2c line	Previously reported	Correct information
Box 12, code	`TT`	`TT`
Box 12, amount	`1500.00`	`500.00`
Boxes 1 to 6	No entry	No entry

Boxes 1 to 6 stay empty because nothing about wages or tax changed: overtime was already in box 1. The instructions say:

For the items you are changing, enter under “Previously reported” the amount reported on the original Form W-2 or the amount reported on a previously filed Form W-2c. Enter the correct amount under “Correct information.”

and, for box 12: "Employers should enter both the code and dollar amount for both fields on Form W-2c." (IRS General Instructions for Forms W-2 and W-3 (2026), Form W-2c)

Steps

Rebuild the right Code TT per employee, workweek by workweek.
List the employees whose figure changes, with the old and new amounts.
Prepare one Form W-2c per employee and one Form W-3c for the batch. "Always file Form W-3c when submitting one or more Forms W-2c."
File with the Social Security Administration and give each employee a copy. "File Forms W-2c and W-3c as soon as possible after you discover an error."

Why speed matters

The employee can deduct only what box 12 code TT shows, so an understated figure costs them the deduction until the W-2c arrives. (IRS FS-2026-13, Q22) For the employer, the per-form penalty rises with the correction date: see penalties.

Do the whole year from a file

Drop a timesheet CSV, paste the register overtime totals, and get a worksheet per employee with the reason for every difference.

Open the tie-out tool

Runs in your browser. Payroll data is never uploaded.

Questions

Must an employer correct a wrong Code TT?

Yes. FS-2026-13, Q11 says the employer must file Form W-2c with SSA and furnish it to the employee as soon as possible.

Can the employee fix it with Form 4852 instead?

No. The IRS says an amount on a substitute Form 4852 cannot be used for the qualified overtime deduction.

Is a small error worth a W-2c?

A safe harbor may apply when no single amount is off by more than $100, but the employee can ask for a corrected form anyway.

Sources

Fetched 2026-11-10. Regulation text was checked against the federal annual edition; links open the current online version.

Updated 2026-11-10. Tickfoot is an information tool, not tax, legal or professional advice.