How backup withholding starts, and how to stop it
Backup withholding is the enforcement mechanism behind Form W-9. Hand over a correct, signed form and you are paid gross. Send nothing, send it unsigned, or send a TIN that does not match, and the payer has to take 24% off the top and send it to the IRS.
The rate, the statute, and how it stops
- Rate
- 24% of the reportable payment
- Legal basis
- IRC section 3406
- Who withholds
- The payer, out of what it owes you
- Is it a penalty?
- No. It credits against the tax you owe
- How to stop it
- Supply a valid, signed W-9 with a matching name and TIN
- Where it shows up
- Federal income tax withheld on your Form 1099
- Threshold
- None. A missing certification triggers it whatever the payment size
The four triggers
Backup withholding starts for one of four reasons, and only the first two are inside your control on the day somebody asks you for a W-9. The other two begin with the IRS writing a letter, which means they are usually well underway before you hear about them. Once any of the four is live the payer has nothing left to decide: the rate comes off the top mechanically, payment after payment, and calling accounts payable to explain your situation changes none of it, because the person you reach has no authority to switch it off and would be personally creating exposure for the company if they did. Missing paperwork accounts for the overwhelming majority of what happens in practice, and missing paperwork is also the cheapest of the four to cure. Send the form.
Payers get accused of being difficult about W-9s, and the accusation is misplaced. A payer that fails to withhold when required can be held liable for the tax it should have withheld, plus penalties. So when accounts payable says it must withhold 24% until your form arrives, it is quoting the law rather than opening a negotiation.
What is subject to it
Backup withholding tracks 1099 reporting closely, so the quick test is whether the payment would land on an information return at all. Wages sit outside it because ordinary payroll withholding already does that job. Real estate proceeds are reportable but run on their own withholding rules. Everything else below is exposed from the moment a valid certification is missing.
| Payment type | Reported on | Subject to backup withholding? |
|---|---|---|
| Nonemployee compensation | 1099-NEC | Yes |
| Rents | 1099-MISC box 1 | Yes |
| Royalties | 1099-MISC box 2 | Yes |
| Other income, prizes and awards | 1099-MISC box 3 | Yes |
| Interest | 1099-INT | Yes |
| Dividends | 1099-DIV | Yes |
| Broker and barter proceeds | 1099-B | Yes |
| Payment card and network transactions | 1099-K | Yes |
| Gross proceeds paid to an attorney | 1099-MISC box 10 | Yes |
| Wages to an employee | W-2 | No. Ordinary payroll withholding applies instead |
| Real estate sale proceeds | 1099-S | Reportable; withholding rules differ. Detail |
The B notice cycle
When a name and TIN pair fails IRS matching, a defined sequence follows, and every step in it runs on a deadline the payer cannot move. Miss one and the payer’s own reasonable cause argument gets thinner, so the deadlines get taken seriously by people who are otherwise relaxed about paperwork. That is the pressure behind the sudden urgency in your client’s emails about a form you were sure you had already sent months ago; from their side, a clock started when an IRS notice landed in the mailroom and they have a few weeks to get a corrected form out of you. Publication 1281 sets out the whole cycle, and knowing where you sit in it changes your answer: at step three a fresh W-9 cures the problem, while at step five a fresh W-9 achieves nothing at all.
The payer files a 1099 with a mismatched name and TIN
Nobody usually notices at the time, because the IRS matching happens after filing.
The IRS sends the payer a CP2100 or CP2100A notice
Listing every payee whose name and TIN did not match. These arrive roughly twice a year.
The payer sends you a first B notice
Within 15 business days, together with a fresh Form W-9. You must return a corrected W-9. If the problem is your SSN, you supply a corrected W-9; if the IRS record itself is wrong, you may need to fix it with the Social Security Administration first.
No response means withholding begins
The payer must start 24% backup withholding on reportable payments no later than 30 business days after the date of the CP2100 notice, or the date the payer received it, whichever is later, and continue until you correct the record. Both that deadline and the 15-business-day B notice deadline run from the same event; the second does not begin when the first ends.
A second B notice raises the bar
If the same payee mismatches again within three calendar years, the second notice requires validation from the IRS or SSA, and a fresh W-9 alone is no longer sufficient. For an SSN the payee supplies a copy of their Social Security card, and Publication 1281 adds a recency condition: that copy must be dated no earlier than six months before the date of the second B notice, otherwise a newly issued card must be requested from the SSA. For an EIN the payee obtains an IRS Letter 147C.
If your name changed and you never updated it with the Social Security Administration, sending corrected W-9s to a dozen clients accomplishes nothing; all twelve will mismatch again on the next filing. Update the SSA record first. TIN matching
The payer-side procedure, including what each notice must enclose and the different cure the second one demands, is set out at first and second B notice.
How to stop it
| Why it started | What ends it |
|---|---|
| No W-9 on file | Send a complete, signed W-9. Withholding stops on payments made after the payer has it |
| Unsigned or incomplete W-9 | Send a corrected, signed form |
| Name and TIN mismatch, first B notice | A corrected W-9 with the right pair. Fix the SSA or IRS record first if that is the source |
| Second B notice within three years | IRS or SSA validation. For an SSN, a Social Security card copy dated no earlier than six months before the notice; for an EIN, an IRS Letter 147C |
| IRS-notified under-reporting of interest or dividends | Resolve it with the IRS and obtain confirmation that you are no longer subject to withholding |
The payer does not reverse withholding it has already taken, because that money has gone to the IRS. You recover it as a credit when you file. Your client cannot hand it back.
Recovering what was withheld
The withheld amount appears on your Form 1099 as federal income tax withheld. You report it on your return alongside your estimated payments, where it reduces your balance due or produces a refund if you have overpaid, so nothing is lost in the end. What it costs you is the delay. Money that should have reached your account in March sits with the Treasury until you file the following spring, and for a small business carrying that gap across a full year the effect can be the difference between making payroll comfortably and financing it on a credit line at whatever rate the bank feels like charging. The cost never appears as a line item anywhere, so it gets underrated.
24% is a flat rate applied to gross payments, while your actual liability depends on your profit after expenses, your other income, and self-employment tax. It may come out higher than 24%, or lower. Keep making estimated payments as if the withholding were not happening, then reconcile at the end of the year.
The definition doing the work in this section is set out at what counts as a reportable payment.
If you are the payer
- Collect the W-9 before the first payment; everything downstream gets easier.
- Use IRS TIN Matching to validate pairs before filing season.
- Withhold 24% where you have no valid certification, and deposit it under your payroll deposit schedule.
- Report withheld amounts on the relevant 1099 and on Form 945, the annual return of withheld federal income tax.
- Respond to CP2100 notices inside the 15-business-day window.
- Track second B notices separately. A fresh W-9 will not clear one; those need IRS or SSA validation.
- Read Publication 1281, which covers the whole procedure.
A payer that fails to obtain a TIN and fails to withhold can be liable for the amount it should have withheld, plus information return penalties. That exposure is why the request lands in your inbox before you have even sent an invoice.
Frequently asked questions
What is the backup withholding rate?
24% of the reportable payment. It has been 24% since 2018 and did not change for 2026.
Is backup withholding a penalty?
No. It is a prepayment of your tax, credited against what you owe when you file, so the money is not lost. What it disrupts is cash flow. The separate $50 penalty for failing to furnish a TIN is a real penalty; the withholding itself is not.
How do I stop backup withholding?
Send a valid W-9 if it started because none was on file. If the IRS notified the payer of an incorrect TIN, send a corrected W-9 with the name and number that match the government record. Under-reported interest or dividends work differently: there you need the IRS to confirm the matter is resolved before withholding stops.
Does the new $2,000 threshold mean small payments escape withholding?
Partly, though the mechanism matters more than the headline. IRC 3406 applies to reportable payments, and for ordinary business payments a payment becomes reportable at the section 6041 threshold, so payments to a payee who stays under $2,000 for the year generally fall outside both. Neither you nor the payer knows the annual total in advance, though. Once the threshold is crossed the obligation is already live.
Can I get withheld amounts back?
The payer reports them as federal income tax withheld on your Form 1099, and you claim the credit on your return. If that produces an overpayment, you get a refund.
General information, not tax advice. This page explains a federal tax form in plain English. It is not legal, tax, or accounting advice, and W9Form.org is not affiliated with the IRS. Verify everything against the official Form W-9 page on IRS.gov and speak to a licensed professional about your own situation. How we source and review these pages.