Every filing season has one small box that swallows an outsized share of staff hours. This year, keep your eyes on Box 12, Code TT of the Form W2.
That code is where employers report qualified overtime compensation, and it is the starting point for the new overtime deduction. The key word is starting. Treating the Code TT figure as the deduction itself is the fastest way to build a stack of returns you will have to reopen in March.
The deduction is not for overtime pay. It is for the premium portion of overtime pay that federal wage law requires. Picture a client whose regular rate is $20 an hour. Time and a half is $30, and the premium is the extra $10. If the employer happens to pay double time at $40, the qualifying premium is still $10. Anything above what the law demands is simply wages.
Then come the limits. The deduction is capped at $12,500, or $25,000 on a joint return, and it phases out as income rises. Employers report the amount without applying any of that, so the work of getting to the real figure lands on your desk.
The ugly cases are the ones where the form is wrong. If a client's employer leaves out the overtime or understates it, the fix is a corrected W2c from the employer. A substitute form filed by the client does not solve it. That leaves you with three options: extend, wait, or file now and amend later. None of them is fun in the second week of April.
An overstated Code TT is a different trap. A client can only deduct overtime actually received, so a figure that looks too high should be questioned, not carried to the return.
Expect confusion about eligibility, too. Salaried exempt employees, state law overtime, and contractual premiums for holiday or weekend shifts will all raise questions about what counts.
Add a Code TT line to your organizer and your preparer review checklist. Ask clients to send their final pay stub of the year along with the W2 so you can compare year-to-date overtime against what the employer reported. Teach staff to flag any return where the code is present but the pay records do not match, or where a client mentions heavy overtime and the box is empty.
Decide now how you will handle a missing figure. Will you extend automatically, or give clients a deadline to get a corrected form? Put that policy in your engagement letter so you are not negotiating it with each person.
The name "no tax on overtime" is doing clients a disservice. Their paystubs still show overtime as taxable wages, and withholding does not change unless they update their Form W4. Some will expect a bigger refund than the math delivers. A short note in your fall client email explaining that the deduction comes through on the return, covers only the premium, and has income limits will save you dozens of awkward phone calls.
Filing seasons rarely stall because the law is hard. They stall because a form arrives wrong and nobody planned for it. A twenty-minute review process built in November costs far less than a backlog in April.