Free Tool

CP2100 B-Notice Triage Tool

Upload your CP2100 notice extract and get a complete action plan: deadlines for every payee, 1st vs. 2nd B-Notice classification, backup withholding start dates, and a prioritized outreach queue. Built from IRS Publication 1281.

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CP2100 Notice Date (from the notice itself)

Date You Received It (leave blank if same as notice date)

Per IRS Pub. 1281, deadlines run from the later of the notice date or the date you received it. If you document the date received and it's later, use that date to gain extra time.

Current CP2100 File (required)

Upload current CP2100 extract

Pipe-delimited .txt from IRS CD/DVD, or paste below

Prior-Year CP2100 File (optional: enables auto 1st/2nd classification)

Upload prior-year CP2100 extract

If a TIN appeared on this file too, it's a 2nd B-Notice

Prior-Prior-Year CP2100 File (optional: detects 2-in-3 year rule)

Per IRS Pub. 1281: you generally do not have to send a B-Notice more than twice within 3 calendar years to the same account. If a payee that is classified as a 2nd B-Notice on the current notice also appeared on the prior-prior notice (i.e., you already sent a 2nd B-Notice within the 3-year window), no further B-Notice is required.

Upload prior-prior-year CP2100 extract

2nd B-Notices also on this file = 2-in-3 rule, no action needed

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Action Deadline Calendar

B-Notice Send Deadline

Send First B-Notice + W-9 (1st notification) or Second B-Notice (2nd notification) within 15 business days

Latest BWH Start Date

Begin backup withholding (24%) on payees who haven't responded within 30 business days. You may begin earlier.

BWH Stop (after W-9 received)

30 calendar days

after receiving signed W-9 (1st notice) or TIN validation from SSA/IRS (2nd notice)

Stop BWH within 30 calendar days of receiving required documentation. You may stop earlier.

These deadlines apply per-account. The B-Notice send deadline and BWH start deadline are based on the later of the notice date or date received. Second B-Notice accounts require IRS Letter 147C or SSA Social Security card copy, not just a W-9.

Notice Breakdown by TIN Status

Prioritized Payee Action Queue

#	TIN	Payee Name	Account	Form Type	TIN Status	B-Notice	Send By	BWH Starts

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Required Actions by Notice Type

Penalty Exposure Analysis

IRC §6721 · Based on Pub. 1586

Business size:

Filing year:

Correction scenario:

Reasonable cause applies to:

Issue Category	Records	Penalty / Return	Gross Exposure	After Reasonable Cause	Notes

Penalty rates per IRS Pub. 1586 (Rev. 7-2023), IRC §6721, and IRS Rev. Proc. 2024-40 inflation adjustments. 2025 rates: Tier 1 $60/return (max $630,500 small / $3,183,000 large), Tier 2 $130/return (max $1,891,500 small / $3,783,500 large), Tier 3 $330/return (max $3,783,500 large / $1,261,000 small). Intentional disregard: $630/return (2025), no cap. These are estimates. Consult a tax professional for your specific situation. View IRS Pub. 1586 ↗

CP2100 File Format (IRS Pub. 1281, Part 9)

The CP2100 CD/DVD extract uses pipe-delimited Payer B Records. Each line represents one payee with a missing or incorrect TIN. The key fields this tool uses:

BWH TIN Status

1 = Missing TIN

2 = Not currently issued

3 = Incorrect Name/TIN

TIN Indicator

1 = Payer indicated EIN

2 = Payer indicated SSN

0 = No TIN indicated

Deadline Rules (Pub. 1281)

Send B-Notice: 15 business days

Start BWH: 30 business days

Stop BWH: 30 calendar days after W-9

This tool also accepts a simplified format: one record per line, fields separated by pipes. Minimum required fields: TIN | BWH Status | Name Line 1. Extra fields are parsed if present.

Automate your entire B-Notice response workflow.

TIN Comply's managed B-Notice service handles everything: TIN matching to confirm mismatches before you send notices, W-9 collection and tracking, deadline monitoring, and second B-Notice escalations with SSA/IRS validation tracking.

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Questions people ask

What is the difference between a first and a second B-Notice?

A first B-Notice goes to a payee listed on a CP2100 for the first time in three years; you send the notice with a W-9 and the payee's new W-9 clears it. A second B-Notice goes to a payee listed again within three years; a W-9 is not enough, the payee must get a letter from the SSA (for an SSN) or the IRS (for an EIN) confirming the number.

How long do I have to send B-Notices?

15 business days from the date of the CP2100 notice (or the date you received it, if later) to mail the B-Notices. If a payee does not respond within 30 business days of the notice date, backup withholding at 24 percent starts on their payments.

Do I have to send a B-Notice to every payee on the list?

Only to payees whose records match what you filed. If the IRS listing shows a TIN you did not report, or you already have a corrected W-9 dated after the filing, no notice is required for that payee; keep the documentation. The triage tool separates those cases.

Where does this tool get its rules?

From IRS Publication 1281, Backup Withholding for Missing and Incorrect Name/TIN(s), which sets out the first and second notice rules, the deadlines and the solicitation requirements. Your notice file is read in the browser and never uploaded.