IRS Incorrect TIN Notice: B Notice and Backup Withholding

October 17, 2026 · 3 min read

Educational information only. Not tax, legal or financial advice. We are not the IRS and are not affiliated with it. Check IRS.gov and consider a qualified tax professional. Sources read October 17, 2026. Anything marked expected should be re-checked. Examples use made-up numbers. This page contains no affiliate links.

Short answer: The IRS General Instructions say that when the IRS tells you a payee's name/TIN combination on a Form 1099 you filed is incorrect, you must promptly furnish a "B" notice (or an acceptable substitute) to the payee. You may withhold after receiving the notice, but you must withhold on reportable payments made more than 30 business days after you received it. Stop within 30 days after you receive a certified Form W-9. Nonemployee compensation is subject to backup withholding.

The timeline (IRS wording)

1. Notice arrives from the IRS: the payee's TIN is incorrect.
2. Promptly send the B notice (or substitute); Pub. 1281 and Regulations section 31.3406(d)-5 give details.
3. Day 31 business days onward: withhold (24%) on reportable payments unless you've received a certified Form W-9 (or similar form where the payee certifies the TIN).
4. Stop within 30 days after you receive the certified W-9.

Two notices in three years

If you receive two incorrect TIN notices within 3 years for the same account, the IRS says to follow Regulations section 31.3406(d)-5(g) and Pub. 1281 (different procedures).

"Applied for" TINs

A payee can write "Applied For" on a Form W-9, but the IRS says the 60-day exemption from backup withholding applies only to interest, dividends and certain payments on readily tradable instruments. Nonemployee compensation is subject to backup withholding even if the payee has applied for a TIN. If you don't get a TIN within the stated period and haven't started, begin withholding.

Reporting what you withheld

Report backup withholding on Form 945 and, on each Form 1099 (including 1099-NEC, box 4), report the amount withheld, even if the payment is below the normal reporting threshold. The EIN on the 1099s must match the EIN on Form 945. Per the 2025 General Instructions, Form 945 for 2025 is due by February 2, 2026; the equivalent date for 2026 withholding is expected to be February 1, 2027 (a Monday, since January 31 is a Sunday), not confirmed.

Prevent it: TIN Matching

The IRS says payers who validate TIN and name combinations before filing generally receive fewer backup withholding notices; the IRS offers a TIN Matching program.

Made-up example

A notice arrives about a contractor whose TIN doesn't match. You send the B notice. The contractor returns a signed W-9 within the window: you stop (or never start). If not, withhold 24% on payments after 30 business days.

Related

W-9 explained · Box-by-box guide (box 4) · Penalties

FAQ

Do I have to withhold at once?

The IRS says you may, but must after 30 business days.

Can I correct the form instead?

The IRS encourages filing corrections for incorrect or missing TINs even where reasonable cause exists.

What we could not verify