TIN Matching & Verification Guide

What is the process for TIN matching?

TIN Matching is the process of verifying the TIN (Taxpayer Identification Number) furnished by the payee/recipient against the name/TIN combination contained in the IRS database. A TIN may be an Employer Identification Number (EIN), a Social Security Number (SSN), or an Internal Revenue Service Individual Taxpayer Identification Number (ITIN).

How does the process work?

Enter your payer and recipient data
On the Payer/Recipient profile page, select the option to "Validate Now"
Confirm you want to add the TIN Matching request to your Cart
Go to your Cart, enter your credit card information if not yet added, and checkout. TIN matching is $1.00/per record
The data you provided is verified against the IRS database
Within approximately two to five business days, you can review the payer or recipient profile in your account to see the result, which will display whether the TIN match was returned as valid or invalid with the date of verification
Contact your recipients to reconcile any differences
Edit the data to correct any mismatches
Complete your forms and check out

Please note that if it is close to the filing deadline, we recommend that you select the recipients you want to Name/TIN match AND checkout your forms simultaneously. Depending on how close to the filing deadline your forms are accepted, you may be notified of any Name/TIN mismatches after the IRS/SSA filing deadline. Once you confirm the correct information from your recipient, you will then need to enter a correction to report the correct Name/TIN combination and submit the corrected form. While this will incur a correction fee, you will avoid a possible penalty for missing the IRS/SSA filing deadline.

Our optional subscription plans include some level of TIN matching. The Plus Subscription plan includes 250 free TIN matches and the Premium Subscription plan includes unlimited TIN matches. The results should be displayed within the payer/recipient profile within two to five business days. Please allow two to five business days for TIN Matching to complete before completing the checkout to file your forms. Doing so will allow you time to correct the Name/TIN mismatches prior to submitting the form.

What is a CP2100 or CP2100A Notice?

It is a notice that tells a payer that he or she may be responsible for backup withholding. The CP2100 or CP2100A Notice includes a listing(s) of the information returns you filed that had missing, incorrect, and/or not currently issued TIN(s). You should compare the listing(s) to your records to determine which of the following required actions you must take. Generally, you must obtain a TIN from a payee even for a “one-time” transaction. If you do not, the law allows IRS to charge a penalty. Large volume filers will receive a CD or DVD data file CP2100, mid-size filers receive a paper CP2100, and small filers receive a paper CP2100A.

Large Filer = 250 or more error documents
Mid-Size Filer = Between 50 and 249 documents
Small Filer = Less than 50 error documents

What should I do if I receive a CP2100 or CP2100A Notice?

Compare the listing(s) with your records. For missing TINs: If you have not started backup withholding, begin to do so immediately and continue until you receive a TIN. You must make up to three solicitations for the TIN (initial, first annual, second annual) to avoid a penalty for failing to include a TIN on the information return. For incorrect TINs: Compare the accounts on the listing with your business records. You must begin backup withholding on all reportable payments to the payee no later than 30 business days after you have received the CP2100 or CP2100A Notice. You must stop backup withholding on payments within 30 calendar days after you have received the required certification (Form W-9) from the payee or TIN validation from the SSA or the IRS, if it was a second notification. At your option, you may start and stop backup withholding at any time during these 30-day periods, in order to avoid a penalty for failure to include the correct TIN on an Information Return. If they agree, send the appropriate “B” Notice to the payee. If an account does not agree, this could be the result of a recent update to SSA records, an error in the information you submitted, or an IRS processing error. If this type of error occurred, the only thing you should do is correct or update your records, if necessary. Remember: You do not have to call or write to the IRS to say that you made the correction or update to your records.

What is a “B” Notice?

A “B” Notice is a backup withholding notice. There are two “B” Notices -- the First “B” Notice and the Second “B” Notice. You must send the First “B” Notice and a Form W-9 to a payee after you receive the first CP2100 or CP2100A Notice with respect to this account for soliciting a correct Name/TIN combination. You must send the second “B” Notice to a payee after you receive a second CP2100 or CP2100A Notice within a 3 calendar year period. The text of the Second “B” Notice is different from that of the First “B” Notice. The Second “B” Notice tells the payee to contact IRS or SSA to obtain the correct Name/TIN combination. The mailing of the second notice should not include a Form W-9. The payer must receive validation of the payee’s Name/TIN combination from SSA or IRS after sending the second “B” Notice. Payees should be instructed regarding how to request validation of their name/TIN combinations. Generally, you do not have to send a “B” Notice more than two times within three calendar years to the same account. It is your responsibility to send the appropriate “B” Notice to the payee, when required, to obtain the correct Name/TIN. This information may not be solicited by telephone. You need a TIN that the payee certifies as correct on Form W-9 in order to stop current backup withholding or prevent backup withholding from starting.

How to issue a First “B” Notice

Send the First “B” Notice, Form W-9, and an optional reply envelope to the payee within 15 business days from the date of the CP2100/CP2100A Notice or the date you received it (whichever is later). Date the “B” Notice no later than 30 business days after the date of the CP2100/CP2100A Notice or the date you received it (whichever is later). The outer mailing envelope must be clearly marked “IMPORTANT TAX INFORMATION ENCLOSED” or “IMPORTANT TAX RETURN DOCUMENT ENCLOSED.”
Make sure that necessary information such as the date, account number, and BWH rate are on the “B” Notice before mailing it to the payee. If you do not include the optional reply envelope be sure to provide return address information in your mailing.
Update your records with the corrected information you receive from the payee and include it on any future information returns you file. Do not send the signed Form W-9 to the IRS.
Begin backup withholding on payments made to payees who do not return a signed Form W-9 in response to the First “B” Notice, no later than 30 business days after the date of the CP2100/CP2100A Notice or the date you received it (whichever is later). However, you may begin backup withholding the day after the date you receive the CP2100 Notice. Stop backup withholding no later than 30 calendar days after you receive the signed Form W-9 from the payee. You may stop backup withholding any time within that 30 calendar day period.

How to issue a Second “B” Notice

Send the Second “B” Notice and an optional reply envelope to the payee within 15 business days after the date of the CP2100/CP2100A Notice or the date you received it (whichever is later). Date the “B” notice no later than 30 business days after the date of the CP2100/CP2100A Notice or the date you received it (whichever is later). Do not send a Form W-9. The outer mailing envelope must be clearly marked “IMPORTANT TAX INFORMATION ENCLOSED” or “IMPORTANT TAX RETURN DOCUMENT ENCLOSED.”
An individual payee must provide the payer with a copy of a Social Security card with his or her correct name and SSN. Payers may rely upon a Social Security card as being correct only if the name and SSN combination appearing on the card differ from the name and SSN combination appearing on the second B notice, or if there is a date appearing on the Social Security card that is no earlier than six months prior to the date of the second B notice. If the TIN is an EIN, the payee must contact the IRS to get his or her employer identification number validated on the IRS Letter 147C. A “Letter 685C” is requested from the IRS by the payee to validate an ITIN. The payee then sends a copy of the “Letter 685C” received from the IRS to the Payer. A “Letter 096C” is requested by the payee from the IRS to validate an ATIN. The payee then sends a copy of the “Letter 096C” received from the IRS to the payer.
Allow 30 business days after the date of the Second “B” Notice to receive a copy of a Social Security card described in paragraph 2 or Letter 147C from the payee. Begin backup withholding on payments made to the payee if you do not receive a copy of a Social Security card or Letter 147C by the 30th business day. You may, at your option, begin backup withholding anytime during the 30 business day period. You must continue to backup withhold until you receive the validation. Stop backup withholding no later than 30 days after you receive the required validation. You may stop backup withholding anytime within the 30 calendar day period after receiving validation.

Third and Subsequent Notices

Generally, you may ignore a third or subsequent notice of missing or incorrect TIN(s) if you completed the actions for the First and Second “B” Notices and the incorrect payee name and TIN combination and account number remain the same. However, if the CP2100/CP2100A Notice and listing(s) relate to the same payee, but with a different Name/TIN combination than on the “first” and “second” notice, you must treat the notice as a “first” notice.

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TIN Mismatches: How to Respond to IRS Notices CP2100 and CP2100A

FAQs

How is a Name/TIN mismatch identified?

A Name/TIN combination is incorrect if it does not match, or cannot be found, on IRS or SSA files. For example, a Name/TIN mismatch occurs when an individual name is submitted with a TIN not associated with the individual name provided. A TIN is not interchangeable with different names. A business EIN must be used for a partnership, corporation, or non-disregarded Limited Liability Company (LLC). An SSN must be used with an individual name (In first name line). A Sole Proprietor must always provide his/her individual name. A Sole Proprietor may provide his/her Doing Business As (DBA) name (in second name line) in addition to the required individual name together with the matching SSN.

What should I do if a payee refuses or neglects to provide a TIN?

Begin backup withholding immediately on any reportable payments. Do the required annual solicitation (request) for the TIN. Backup withhold until you receive a TIN.

How do I know if a TIN on my account is incorrect?

After the submission of Form 1099 information returns, the IRS will send you a CP2100 or a CP2100A Notice and a listing of incorrect Name/TIN(s) reported on those forms.

How do I know which “B” Notice to send?

If this is the first CP2100 or CP2100A Notice you have received with respect to this account, you must provide the payee with (1) the First “B” Notice and (2) a copy of Form W-9 (or acceptable substitute). You may also provide an optional reply envelope. Your outside mailing envelope must be clearly marked “IMPORTANT TAX INFORMATION ENCLOSED” or “IMPORTANT TAX RETURN DOCUMENT ENCLOSED.”

If this is the second CP2100 or CP2100A Notice you have received within three calendar years with respect to this account, you must provide the payee with the Second “B” Notice. Do not include a Form W-9. You may also provide an optional reply envelope. Your outside mailing envelope must be clearly marked “IMPORTANT TAX INFORMATION ENCLOSED” or “IMPORTANT TAX RETURN DOCUMENT ENCLOSED.”

Do I have to mail a Second “B” Notice if I receive the second CP2100 or CP2100A Notice in the same calendar year as the first notice?

No. You may disregard the second CP2100 or CP2100A notice, even if it relates to a different tax year than the first notice. You also have no obligation to mail a second “B” Notice if you receive the second CP2100 or CP2100A Notice in a different calendar year than the first, but both of the CP notices relate to the same payee’s account for the same calendar year.

What should I do if a “B” Notice is returned as “undeliverable”?

You must begin backup withholding. However, try to get the correct address for the payee and remail the notice. If you cannot find the correct address, keep the undelivered notice with your records for a period of three years, in order to track the “two-in-three-year” rule or, until you have obtained a valid address.

Updated: 10/28/2026