Backup Withholding: The 24% Rule and How to Stop It

TL;DR: Backup withholding is a flat 24% that the IRS requires a payer to hold back from certain payments, usually the ones reported on a 1099, and send straight to the IRS instead of to you. It kicks in when your taxpayer identification number is missing or wrong, or when the IRS has told the payer you underreported interest or dividends. It is not a penalty or an extra tax: the amount is a prepayment credited on your return. You stop it by fixing the reason, most often by returning a correct, signed Form W-9.

What Backup Withholding Is and Isn't

Backup withholding is a mandatory federal income tax withholding on reportable, non-payroll payments, authorized by Internal Revenue Code section 3406. When it applies, the payer keeps back a flat share of what they owe you and remits it to the IRS under your taxpayer identification number (TIN).

The rate is 24%. It has been 24% "for all subject payments after December 31, 2017" (IRS Publication 1281), when the Tax Cuts and Jobs Act cut it from the old 28%. The IRS states the figure plainly: "The current backup withholding rate is 24% of payments you make to a payee" (IRS, Understanding your CP2100 or CP2100A notice).

The word "backup" matters. An employee has income tax withheld from every paycheck. A freelancer, a contractor, or an investor normally receives the full payment and settles up at tax time. Backup withholding is the fallback the IRS switches on when it cannot trust that the second group will report the income correctly, because the paperwork does not add up. The money is not lost. It shows up as federal income tax withheld and reduces your final bill dollar for dollar, exactly like paycheck withholding.

What Payments Are Subject to Backup Withholding

Backup withholding attaches to the categories of income reported on a 1099, not to wages. The IRS lists the payments it can apply to (IRS, Topic no. 307, Backup withholding):

For most self-employed readers the line that matters is nonemployee compensation: the money a client pays you for services, reported on a 1099-NEC. Wages on a W-2 are never subject to backup withholding, because they already carry ordinary payroll withholding.

The Four Things That Trigger It

The IRS runs backup withholding through two programs, and between them there are four triggers (IRS, Topic no. 307):

1. You don't give the payer your TIN in the required manner. No W-9, or a W-9 with the number left blank.
2. The IRS notifies the payer that the TIN you gave is incorrect. The name and number you certified do not match IRS records. This and the missing-TIN case make up the "B" program (BWH-B, the B is for "incorrect data").
3. The IRS notifies the payer to start withholding because you underreported interest or dividends. This is the "C" program (BWH-C). The IRS reaches it only after a long paper trail, described below.
4. You fail to certify that you are not subject to backup withholding for underreporting interest and dividends. That certification is Part II of the W-9.

The first two are ordinary, and they are the ones a freelancer trips. A single-digit typo in an EIN, or a business name that does not match the number, is enough. The how-to-fill-out-w9 guide walks the classification box and the SSN-versus-EIN choice where these mismatches usually start.

The C program is different. The IRS does not switch it on for a paperwork error; it switches it on after you have ignored several notices. "If you don't correctly report your interest and dividends on an income tax return, the IRS will send at least four notices over a period of at least 120 days asking you to correct the unreported or underreported interest and dividend income" (IRS, Backup withholding "C" program). The last of those, the C-notice, tells you the withholding is coming.

If You're the One Being Paid: How to Stop the 24%

Say you invoice a client $3,000 and backup withholding applies because your W-9 did not arrive or the number bounced. The client pays you $2,280 and sends $720 (24% of $3,000) to the IRS under your TIN. That $720 is not gone. It lands in box 4, "Federal income tax withheld," of the 1099 the client files, and you claim it as a payment on your Form 1040. If your actual tax on that income is less than $720, the difference comes back as part of your refund. The cost to you is timing: you have handed the government cash months before you would otherwise have paid it, and you get it back only when you file.

To stop the withholding on future payments, correct the reason you became subject to it. The IRS gives three paths, matched to the three ways in (IRS, Backup withholding):

• Missing or wrong TIN: give the payer a correct, signed W-9. Make sure the name on Line 1 matches the number in Part I, because a name/number mismatch is the single most common reason a 1099 filing bounces. If you use an EIN, confirm it against your IRS confirmation letter; the how to get an EIN guide covers where that number comes from.
• Underreported interest or dividends: resolve the underreported income and pay what you owe, or file the missing returns.
• Failure to certify: sign Part II of the W-9. You are certifying, among other things, that the IRS has not told you that you are subject to backup withholding. If it once did and later cleared you, you can sign; if a C-notice is currently in force, you cannot.

Once you fix the cause, the payer is required to stop the withholding within 30 business days.

If You're the One Paying a Contractor: The CP2100 Timeline

Flip the roles. You hire a contractor, pay them, and file a 1099-NEC. Months later the IRS mails you a CP2100 or CP2100A notice listing that contractor because "the payee's name and taxpayer identification number (TIN) on your information return is missing or doesn't match our records" (IRS, CP2100 notice). Now the clock starts, and the deadlines are specific (IRS Publication 1281):

• Within 15 business days of the notice date, send the payee the First "B" Notice and a fresh Form W-9.
• Begin backup withholding at 24% no later than 30 business days after the CP2100 date on payments to any payee who does not return a signed W-9.
• Stop backup withholding within 30 business days of receiving the corrected, signed W-9.
• If the same payee appears on a CP2100 a second time within three years, send the Second "B" Notice. This time a plain W-9 is not enough: the payee must provide a Social Security card copy or an IRS Letter 147C validating the name and number.

You report the tax you withheld in box 4 of the contractor's 1099-NEC, and you pay it to the IRS on Form 945, Annual Return of Withheld Federal Income Tax, which covers "federal income tax withheld (or required to be withheld) from nonpayroll payments," backup withholding included. Form 945 is due January 31 of the following year, shifting to the next business day when that date falls on a weekend, with an extension to February 10 if you deposited all the tax on time during the year. Deposits go through the electronic system, and if your total for the year is under $2,500 you can pay with the return instead of depositing.

Here is the arithmetic. You paid a contractor $5,000 over the year and did not get a usable W-9. At 24% you must withhold $1,200: the contractor receives $3,800, you remit $1,200 on Form 945, and box 4 of their 1099-NEC reads $1,200. Skip that duty and the IRS can assess the $1,200 against you, the payer, not the contractor, plus penalties. The paperwork is cheaper than the exposure.

Common Misconceptions

"Backup withholding is a penalty." It is not. It is a prepayment of the payee's own income tax, credited on their return. The only cost is the lost use of the cash until they file. Penalties are separate, and they fall on the party that failed a duty: a payee who furnishes a wrong TIN can face a $50 penalty per failure, and a payer who ignores a valid backup-withholding obligation is liable for the tax they should have withheld.

"A signed W-9 makes me exempt." A correct, signed W-9 prevents the missing-and-wrong-TIN triggers, which is most cases. It does not override a live C-notice for underreported interest and dividends. And exempt payees are narrow: the W-9 instructions note that "generally, individuals (including sole proprietors) are not exempt from backup withholding." If you are a person being paid for work, assume you are not exempt.

"The contractor is on the hook if I forget to withhold." As the payer, you are. Once a CP2100 puts you on notice, the withholding is your obligation, and the IRS collects the unwithheld amount from you.

How SparkReceipt Fits

Backup withholding lives or dies on records: the W-9s you collected, the 1099s you filed, and the box-4 amounts on both sides. SparkReceipt is the capture-and-organize layer under that, not a payroll service. It does not file Form 945 or run withholding.

What it does do is keep the underlying numbers clean. If you pay contractors, the expense tracker records what you paid each one across the year, so your 1099 totals reconcile instead of being reconstructed from a shoebox in January. If you are the one being paid and a client withholds, the 24% shown in box 4 is federal income tax you have already prepaid; logging your income and payments keeps that visible so it feeds your quarterly estimated tax math rather than surprising you at filing. Digital records also mean the W-9 and 1099 trail is searchable when a CP2100 arrives twelve months later. See pricing to get started.

Frequently Asked Questions

Is backup withholding the same as regular income tax withholding? The mechanism is the same, a prepayment credited on your return, but the trigger differs. Regular withholding comes off every W-2 paycheck automatically. Backup withholding is a fallback the IRS turns on for 1099-type income when your TIN paperwork is wrong or you have underreported interest and dividends.

How do I get backup-withheld money back? You claim it. The amount appears in box 4 of the 1099 the payer files, and you enter it as federal income tax withheld on your Form 1040. It offsets your tax bill dollar for dollar, and any excess is refunded when you file.

What is the backup withholding rate in 2026? 24%, unchanged since the Tax Cuts and Jobs Act set it there for payments after December 31, 2017.

I got a CP2100 notice. Do I withhold immediately? Not on the same day. Send the payee a First "B" Notice and a W-9 within 15 business days, and begin backup withholding no later than 30 business days after the notice date on anyone who has not returned a signed W-9 by then.

Can I be exempt from backup withholding? Some entities are, but the W-9 instructions state that individuals, including sole proprietors, generally are not. Signing a correct W-9 is what keeps ordinary freelancers out of it, not an exemption code.

Which form does a payer use to pay backup withholding to the IRS? Form 945, Annual Return of Withheld Federal Income Tax. The withheld amount is also reported in box 4 of the payee's 1099.

Key Takeaways

• Backup withholding is a flat 24% a payer holds from 1099-type payments and sends to the IRS under your TIN; it is a prepayment credited on your return, not a penalty or an extra tax.
• Four things trigger it: no TIN, an incorrect TIN, an IRS notice about underreported interest or dividends, or a failure to certify on Part II of the W-9.
• If you are being paid, the fix is almost always a correct, signed W-9 with a name that matches the number; the payer must stop within 30 business days.
• If you are paying a contractor, a CP2100 notice starts a clock: B Notice and W-9 within 15 business days, withholding within 30, and payment to the IRS on Form 945 with box 4 of the 1099.
• Wages are never subject to backup withholding, and most individuals, including sole proprietors, are not exempt.