1099ThresholdDesk / 2026 1099-NEC, 1099-K & W-9 Guides / IRS CP2100 & CP2100A Notice Guide: First vs. Second B-Notice & 24% Backup Withholding
IRS CP2100 & CP2100A Notice Guide: First vs. Second B-Notice & 24% Backup Withholding
IRS CP2100 & CP2100A Notice Guide?
When a payer receives an IRS CP2100 or CP2100A TIN mismatch notice, the payer must send a First B-Notice with Form W-9 within 15 business days and begin 24% IRC § 3406 backup withholding within 30 business days if a signed W-9 (or IRS Letter 147C for a Second B-Notice) is not returned.
When a payer receives an IRS CP2100 or CP2100A TIN mismatch notice, the payer must send a First B-Notice with Form W-9 within 15 business days and begin 24% IRC § 3406 backup withholding within 30 business days if a signed W-9 (or IRS Letter 147C for a Second B-Notice) is not returned.
Open 2026 $2,000 vs. $600 1099 & W-9 Reconciler
2026 Compliance Checklist
- Collect Signed Form W-9 Before First Disbursement: Never release a check, ACH, or Zelle payment without a signed W-9 on file, or deduct 24% IRC § 3406 backup withholding.
- Separate IRC § 6050W Card/TPSO Payments: Exclude Stripe, Square, and credit card payments from Form 1099-NEC Box 1.
- Verify State $600 Non-Conformity: Even if a vendor was paid between $600 and $1,999 in 2026 (exempt federally under OBBBA § 70432), verify whether your state still mandates a $600 state 1099 filing.
Frequently Asked Questions
IRS CP2100 & CP2100A Notice Guide?
When a payer receives an IRS CP2100 or CP2100A TIN mismatch notice, the payer must send a First B-Notice with Form W-9 within 15 business days and begin 24% IRC § 3406 backup withholding within 30 business days if a signed W-9 (or IRS Letter 147C for a Second B-Notice) is not returned.