Backup withholding is a federal tax withholding rule that can require a business, financial institution, or other payer to withhold part of certain payments that would not normally have federal income tax taken out.
The current backup withholding rate is 24%. It can apply when a payee does not provide a valid taxpayer identification number, when the IRS determines that a name and TIN do not match, or in certain cases involving underreported interest or dividend income.
For businesses that pay independent contractors or issue Forms 1099, backup withholding is particularly important because failing to withhold when required can make the payer responsible for the amount that should have been withheld.
This guide explains how backup withholding works in 2026, when the 24% rate applies, how Form W-9 relates to the process, what CP2100 and “B” notices mean, and how both businesses and payees can prevent or stop backup withholding.
What Is Backup Withholding?
Most payments made to independent contractors, vendors, investors, and other nonemployees are not subject to normal payroll withholding.
Instead, the recipient generally receives the payment and later reports the income on a federal income tax return.
Backup withholding is an exception.
When certain IRS requirements are not satisfied, the payer may be required to take 24% of the payment and send that amount to the federal government.
It is called “backup” withholding because it acts as a backup method for collecting federal income tax when the IRS cannot reliably associate reported payments with the correct taxpayer or when certain reporting problems exist.
What Is the Backup Withholding Rate in 2026?
The backup withholding rate in 2026 is:
24%
The IRS confirmed in updated 2026 guidance that the current backup withholding rate remains 24%.
Backup Withholding Example
Suppose a business owes an independent contractor $2,500 for qualifying services and the contractor is subject to backup withholding.
The calculation would be:
$2,500 × 24% = $600
The payer would generally:
- Pay the contractor $1,900
- Withhold $600
- Deposit and report the $600 as federal backup withholding
The contractor has not necessarily lost the $600 permanently.
The amount withheld can generally be claimed as federal income tax withheld when the contractor files a federal income tax return.
When Does Backup Withholding Apply?
Backup withholding can apply for several different reasons.
The most common situations involve taxpayer identification numbers and IRS notices.
1. The Payee Does Not Provide a TIN
A payer may need a Taxpayer Identification Number, or TIN, before making certain reportable payments.
A TIN may be a:
- Social Security Number (SSN)
- Employer Identification Number (EIN)
- Individual Taxpayer Identification Number (ITIN)
Businesses commonly request this information using Form W-9, Request for Taxpayer Identification Number and Certification.
If a payee does not provide the required TIN, backup withholding may be required.
2. The TIN Is Obviously Incorrect
A payer may also have to begin backup withholding if the TIN provided is obviously invalid.
The IRS explains that a TIN may be considered obviously incorrect when it:
- Contains fewer than nine digits
- Contains more than nine digits
- Contains alphabetic characters
In these situations, withholding can be required immediately on reportable payments.
3. The Name and TIN Do Not Match IRS Records
A TIN can contain nine valid digits and still create a problem.
The name entered on an information return must correspond correctly with the TIN in IRS or Social Security Administration records.
For example, a contractor might provide:
Business name: ABC Creative Studio LLC
TIN: An SSN belonging to the individual owner
Depending on the entity’s tax classification and the information shown on Form W-9, the business needs to use the correct name/TIN combination when preparing the information return.
If the IRS cannot match the combination, the payer may receive a CP2100 or CP2100A notice.
4. The IRS Determines That Certain Interest or Dividends Were Underreported
Backup withholding may also arise when the IRS determines that a taxpayer failed to properly report interest or dividend income.
The IRS refers to this as its backup withholding “C” program.
A payer may be instructed by the IRS to begin withholding from applicable payments.
5. Required Certification Is Missing
In some circumstances involving interest, dividends, brokerage accounts, or similar payments, taxpayers must certify that they are not subject to backup withholding.
Failure to make a required certification can trigger withholding.
What Does Form W-9 Have to Do With Backup Withholding?
Form W-9 plays a major role in preventing backup withholding problems.
Businesses use Form W-9 to request information such as:
- The payee’s legal name
- Business name, when applicable
- Federal tax classification
- Address
- Taxpayer Identification Number
- Required certifications
A properly completed W-9 helps the payer prepare Forms 1099 using the same identifying information recognized by the IRS.
Businesses should generally collect Form W-9 before or at the beginning of the business relationship, rather than waiting until the end of the year.
This makes it easier to detect missing information before reportable payments have already been made.
What Is a TIN Mismatch?
A TIN mismatch occurs when the combination of the taxpayer’s name and Taxpayer Identification Number reported by the payer does not match IRS or Social Security Administration records.
Importantly, this does not always mean that the number itself is fake or invalid.
The problem may simply be the combination.
For example:
- Incorrect legal name
- Business name used instead of the required owner name
- Typographical error
- Wrong EIN
- Wrong SSN
- Recently changed legal name
- Incorrect entity information
This is why businesses should enter information from Form W-9 carefully rather than relying on informal invoices, emails, or payment-account names.
What Is a CP2100 Notice?
The IRS may send a payer a CP2100 notice after identifying information returns containing missing or incorrect name/TIN combinations.
The IRS states that CP2100 generally applies when the payer filed 50 or more information returns with errors.
The notice provides information that helps the payer identify the affected accounts.
Receiving CP2100 does not mean every listed person automatically owes additional tax.
It means the payer must follow the applicable IRS procedures for correcting the taxpayer information and determining whether backup withholding is required.
What Is a CP2100A Notice?
A CP2100A notice serves essentially the same purpose as CP2100 but generally applies when the payer filed fewer than 50 information returns with errors.
The IRS explains that the instructions contained in CP2100 and CP2100A are generally the same.
The primary distinction is the number of affected information returns.
What Is an IRS “B” Notice?
When a payer receives an IRS notice identifying an incorrect name/TIN combination, the payer may need to send the affected payee what is commonly called a “B” notice.
There are two main versions.
First “B” Notice
The first time a payee appears on an applicable IRS mismatch notice, the payer generally sends:
- A First “B” Notice
- Form W-9 or an acceptable substitute
The payee can generally resolve the issue by properly completing and signing the Form W-9 with the correct information.
Second “B” Notice
The procedure becomes stricter when the same payee is identified again within a specified period.
If a second mismatch occurs within three calendar years, the IRS requires additional validation rather than simply accepting another W-9.
Depending on whether the TIN is an SSN or EIN, the payee may need documentation from the Social Security Administration or IRS verifying the correct information.
When Must a Business Start Backup Withholding?
The exact timing depends on why backup withholding applies.
Missing or Obviously Incorrect TIN
If the payee does not provide a TIN or provides one that is obviously invalid, a payer may have to begin backup withholding immediately on applicable reportable payments.
IRS Name/TIN Mismatch Notice
When the business receives an applicable IRS notice stating that a name/TIN combination is incorrect, the business should follow the notice procedures.
If the problem is not corrected, backup withholding generally must begin on applicable payments no later than 30 business days after receipt of the notice.
How Do You Stop Backup Withholding?
Stopping backup withholding depends on what caused it.
If the TIN Was Missing
The payee generally needs to provide the payer with the correct TIN in the required manner.
If the Name/TIN Combination Was Incorrect
The payee may need to provide a correctly completed and certified Form W-9.
For a second “B” notice, additional verification from the IRS or Social Security Administration may be necessary.
If the Problem Involves Underreported Interest or Dividends
The taxpayer may need to address the underlying IRS issue, which could involve:
- Correcting previously reported information
- Filing a missing return
- Paying tax owed
- Obtaining IRS confirmation that backup withholding should stop
The IRS explains that the appropriate solution depends on the reason withholding began.
How Long Does Backup Withholding Continue?
Backup withholding does not automatically end simply because a new tax year begins.
It generally continues until the condition that triggered it has been resolved.
For name/TIN mismatch situations, IRS guidance generally requires the payer to stop withholding within the applicable period after receiving valid corrected information.
The IRS states that when the payer receives the corrected TIN, withholding should generally stop no later than 30 calendar days after receipt.
Is Backup Withholding an Additional Tax?
Not necessarily.
This is an important distinction.
Backup withholding is federal income tax withheld in advance from the taxpayer’s payment.
When the recipient files a federal income tax return, the amount withheld is generally reported as federal income tax already paid.
If the amount withheld exceeds the taxpayer’s total tax liability, it may contribute to a refund.
If the taxpayer still owes additional tax, the withholding reduces the remaining amount owed.
The backup withholding amount should appear on the applicable Form 1099 or other information statement.
Where Is Backup Withholding Shown on Form 1099?
For common forms such as Forms 1099-NEC and 1099-MISC, backup withholding is reported as federal income tax withheld.
For example, the 2026 instructions for Forms 1099-MISC and 1099-NEC direct payers to report backup withholding in Box 4.
Example
A contractor receives:
Gross nonemployee compensation: $5,000
Backup withholding at 24%: $1,200
Net amount received: $3,800
The information return should reflect both the reportable compensation and applicable federal income tax withheld.
The contractor should not simply report the $3,800 cash received as total gross income.
The payment and withholding are separate tax-reporting items.
What Is Form 945?
Businesses that perform backup withholding also need to understand Form 945, Annual Return of Withheld Federal Income Tax.
Form 945 is used to report federal income tax withheld from certain nonpayroll payments, including payments subject to backup withholding.
This is different from the payroll tax returns generally used to report withholding from employee wages.
The IRS requires backup withholding to be reported on Form 945 and on the applicable information return, such as a qualifying Form 1099.
Does a Business Still File a 1099 When the Payment Is Below the Normal Threshold?
This is an important special rule.
Normally, an information return may not be required if payments remain below the applicable reporting threshold.
However, when backup withholding is actually taken from a payment, the IRS generally requires the payer to file the applicable Form 1099 or Form W-2G even if the payment is below the normal filing threshold.
This prevents the withholding from becoming disconnected from the taxpayer who needs to claim credit for it.
What Changed for Some 1099 Payments in 2026?
Businesses should also be aware that the reporting landscape changed for 2026.
For tax years beginning after 2025, the minimum threshold for reporting certain payments — and associated backup-withholding requirements for those payments — increased to $2,000. The threshold may be adjusted for inflation after 2026.
Not every information-return category uses the same threshold, so businesses should still check the specific instructions for the form and payment involved.
The existence of a $2,000 threshold does not mean every payment under $2,000 is automatically outside all tax or reporting rules.
Which Payments Can Be Subject to Backup Withholding?
Backup withholding can potentially apply to several categories of reportable payments.
Depending on the circumstances, these can include payments reported on forms such as:
- Form 1099-NEC
- Form 1099-MISC
- Form 1099-INT
- Form 1099-DIV
- Form 1099-K
- Form 1099-B
- Form 1099-OID
- Form 1099-PATR
- Certain other information returns
The applicable requirements depend on the payment and the reason withholding is required.
Which Payments Are Generally Excluded?
Backup withholding does not apply to every payment.
The IRS lists several excluded categories, including certain:
- Real estate transactions
- Canceled debts
- Retirement-account distributions
- Long-term care benefits
- Qualified tuition-program earnings
- State and local income tax refunds
- Unemployment compensation
Other withholding systems or separate tax rules may still apply to some of these payments.
Are Employee Wages Subject to Backup Withholding?
Generally, no.
Employee wages use the regular federal payroll withholding system rather than the Form 1099 backup withholding rules.
Employers normally report employee compensation on Form W-2 and calculate withholding under payroll tax rules.
Backup withholding is primarily associated with reportable nonpayroll payments.
Businesses therefore should not use backup withholding rules as a substitute for properly determining whether a worker is an employee or independent contractor.
How Can Businesses Prevent Backup Withholding Problems?
Businesses can reduce many backup-withholding problems through good vendor onboarding and accurate recordkeeping.
Collect Form W-9 Before Making Payments
Do not wait until January to ask contractors and vendors for taxpayer information.
Requesting Form W-9 during onboarding allows time to resolve problems before information returns become due.
Check the Legal Name Carefully
The name used for tax reporting may differ from:
- A brand name
- Store name
- Website name
- Payment-account name
- “Doing business as” name
Use the information provided in accordance with Form W-9 instructions.
Check the TIN Format
A TIN should contain the correct number of digits and should not contain letters.
Obvious errors should be resolved before reportable payments continue.
Keep W-9 Information Secure
Forms W-9 contain sensitive taxpayer information.
Businesses should store these records securely and restrict access to people who genuinely need them for tax compliance.
Respond to IRS Notices Promptly
Ignoring CP2100, CP2100A, or other backup-withholding correspondence can make a relatively simple record mismatch much more serious.
Review notices as soon as they arrive and follow the applicable correction procedures.
What Is IRS TIN Matching?
The IRS provides an electronic Taxpayer Identification Number Matching service for eligible payers and authorized agents.
The service allows eligible businesses to compare taxpayer name/TIN combinations with IRS records before submitting certain information returns.
Forms supported by the program include several common information returns, such as Forms 1099-NEC, 1099-MISC, 1099-INT, 1099-K, and others.
Using TIN Matching can help businesses identify mismatches before filing and may reduce the likelihood of receiving CP2100 notices later.
It does not replace proper Form W-9 collection or other tax-compliance responsibilities.
What Happens If a Business Fails to Backup Withhold?
Businesses should not ignore backup-withholding requirements.
The IRS warns that a payer that fails to collect and pay over required backup withholding may become liable for the amount that should have been withheld.
Additional penalties or interest can also become relevant depending on the circumstances.
This means a payer may effectively end up paying tax that should originally have been withheld from the payee.
Proper W-9 collection and timely action on IRS notices can therefore have a direct financial impact on the business.
What Should a Payee Do After Receiving a “B” Notice?
If you are a contractor, freelancer, vendor, or other payee who receives a “B” notice, do not ignore it.
First, compare the information shown with your tax records.
Check:
- Your legal name
- Social Security Number or EIN
- Business structure
- Information previously provided on Form W-9
For a first “B” notice, the solution may be as straightforward as providing the payer with a properly completed and signed Form W-9.
For a second notice within the applicable three-year period, additional documentation may be required.
What Should You Do If Tax Has Already Been Withheld?
If backup withholding has already been taken from your payments, keep the information return showing the amount withheld.
When preparing your federal income tax return, report the backup withholding as federal income tax withheld.
The IRS specifically states that recipients can claim credit for backup withholding shown on their Forms 1099 or W-2G.
Do not confuse:
Gross income earned
with
Net payment received after withholding
Both figures may matter when preparing your return.
Common Backup Withholding Mistakes
1. Waiting Until Tax Season to Collect Form W-9
By then, the contractor may be difficult to reach and payments may already have been made.
2. Assuming Any Nine-Digit Number Is Acceptable
The taxpayer’s name and TIN combination must match IRS records.
3. Ignoring CP2100 or CP2100A
These notices can create actual withholding obligations.
4. Assuming Backup Withholding Is Optional
Once the applicable requirements are met, the payer may be legally required to withhold.
5. Withholding 24% but Failing to Report It
Backup withholding must be properly deposited and reported, including on Form 945 and the applicable information return.
6. Reporting Only the Net Amount Paid
If $1,200 was withheld from $5,000 of reportable compensation, the underlying reportable payment is not simply $3,800.
7. Assuming Backup Withholding Is a Penalty to the Payee
The amount is generally federal income tax withholding for which the taxpayer can claim credit.
Frequently Asked Questions About Backup Withholding
What does backup withholding mean?
Backup withholding is federal income tax withheld from certain nonpayroll payments when specific IRS conditions apply, such as a missing or incorrect taxpayer identification number.
What is the backup withholding rate for 2026?
The current backup withholding rate is 24%.
Why am I subject to backup withholding?
Common reasons include:
- Failing to provide a TIN
- Providing an incorrect TIN
- Having a name/TIN combination that does not match IRS records
- Certain interest or dividend underreporting
- Failure to provide required certifications
Can backup withholding apply to independent contractors?
Yes. Nonemployee compensation can be subject to backup withholding when the applicable requirements are met.
Can backup withholding apply to Form 1099-NEC?
Yes. Backup withholding on Form 1099-NEC is reported as federal income tax withheld.
Is backup withholding 24% of profit or gross payment?
Backup withholding generally applies to the applicable reportable payment, not to the recipient’s eventual taxable profit after deducting business expenses.
The taxpayer determines taxable income separately when filing a tax return.
Do I get backup withholding back?
Not automatically, but you generally claim the amount as federal income tax already withheld when filing your return.
Whether that results in a refund depends on your overall tax liability and other payments or credits.
What is a B notice from the IRS?
A “B” notice is sent by the payer to a payee after certain IRS notifications involving a missing or mismatched name/TIN combination.
What is CP2100?
CP2100 is an IRS notice sent to certain payers identifying information returns with missing or incorrect taxpayer identification information.
What is CP2100A?
CP2100A serves the same general purpose but is typically used when fewer than 50 information returns contain errors.
Does backup withholding go on Form 945?
Yes. Form 945 is used to report federal income tax withheld from certain nonpayroll payments, including backup withholding.
Can a business avoid TIN mismatch notices?
No procedure can guarantee that a notice will never occur, but collecting accurate Form W-9 information and using the IRS TIN Matching program when eligible can significantly reduce preventable errors.
Final Thoughts
Backup withholding may sound like an obscure tax rule, but it can affect ordinary businesses, freelancers, contractors, investors, and other recipients of Form 1099 payments.
The rate remains 24% in 2026, and common triggers include missing taxpayer identification numbers, incorrect name/TIN combinations, IRS mismatch notices, and certain interest or dividend reporting problems.
For businesses, the best approach is preventive: collect accurate Form W-9 information early, maintain secure records, consider IRS TIN Matching when eligible, and respond promptly to CP2100, CP2100A, and “B” notice requirements.
For recipients, correcting taxpayer information quickly can often prevent or stop backup withholding. And when tax has already been withheld, the amount generally can be claimed as federal income tax withheld on the annual tax return.
Accurate information at the beginning of a contractor or vendor relationship can prevent much larger tax-reporting problems at the end of the year.
