# Responding to CP2100 notices from the IRS

A CP2100 or CP2100A notice from the IRS means the IRS found name and Taxpayer Identification Number (TIN) mismatches in 1099 filings associated with your connected accounts. The notice informs you, as the payer, that you may be responsible for backup withholding, and includes a list of missing, incorrect, or not currently issued payee TINs. The IRS considers a TIN incorrect if the name or number on an account doesn't exactly match a name and number combination in IRS or Social Security Administration files.
## CP2100 notice requirements
Per the [IRS CP2100 guidelines](https://www.irs.gov/individuals/understanding-your-cp2100-or-cp2100a-notice) and [IRS Publication 1281](https://www.irs.gov/pub/irs-pdf/p1281.pdf), a CP2100 or CP2100A notice triggers required compliance steps:
1. Send a B-Notice to each affected payee within 15 business days. The B-Notice instructs the payee to provide a corrected name or TIN.
1. Begin 24% backup withholding on any payee who doesn't respond to the B-Notice.
When using Stripe's 1099 Tax Reporting product, the platform is responsible for CP2100 compliance, including B-Notice and backup withholding obligations.
## Identify affected connected accounts
The IRS may print Stripe account IDs in all caps in the CP2100 notice. Stripe account IDs are case-sensitive, so use a **case-insensitive** comparison when matching the IRS-provided IDs to connected accounts in your integration.
## Restrict activity for non-compliant accounts
Stripe doesn't apply backup withholding, but you can restrict account activity for payees who don't respond to a B-Notice by pausing payouts or charges.
### Collect W-8/W-9 forms
Stripe's [W-8/W-9 collection](https://docs.stripe.com/connect/connect-w8-w9-onboarding) feature helps platforms collect and verify certified tax information and enforces action if a user fails to provide it — for example, pausing payouts at a threshold you define.
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*This article is not legal or tax advice. Consult your tax advisor with any questions about tax reporting.*