DNC Checker: How to Check Numbers Against Federal and State DNC Lists

The National Do Not Call Registry holds more than 250 million numbers. A DNC checker screens your list against DNC data — and flags the TCPA litigators who are known to sue over unwanted calls.

What Is the Federal Do Not Call Registry?

The National Do Not Call Registry is run by the Federal Trade Commission (FTC); the FTC’s Telemarketing Sales Rule and the FCC’s rules under the Telephone Consumer Protection Act (TCPA) both rely on it. Consumers register their phone numbers to opt out of telemarketing calls. Registration does not expire — numbers stay on the list unless the consumer removes them or the number is disconnected and reassigned.

Since its launch in 2003, the registry has grown to about 258 million active registrations (FTC data, fiscal year 2025). Calling a registered number for telemarketing without an exemption (such as an established business relationship or prior express written consent) exposes your business to TCPA statutory damages of $500 per call, up to $1,500 per willful violation.

What a DNC Checker Screens For

A proper DNC checker does more than one list lookup. RealValidito’s DNC Lookup (also available through the API) screens each US number against:

• Federal (National) DNC list — numbers consumers have registered with the national registry
• 6 state DNC lists — Texas, Florida, Pennsylvania, Indiana, Colorado and Wyoming
• TCPA Litigator list — known plaintiffs, attorneys and others connected with telemarketing lawsuits

The TCPA Litigator check is especially important. Some people file many TCPA lawsuits every year, and a single unlawful call or text to one of them can lead to a claim of $500–$1,500 per call.

How to Use a DNC Checker Before Outbound Campaigns

The correct workflow is to scrub your list before every campaign, not once at list acquisition. Numbers are added to DNC lists all the time, so a number that was clean six months ago may be listed now.

1. Export your contact list from your CRM or dialer
2. Submit numbers to DNC Lookup — individually, via API (up to 1,000 per request), or in bulk via CSV (up to 50,000 rows per file, one Phone column)
3. Use the Cleaned download (or filter out numbers marked Federal (National) DNC or TCPA Litigator)
4. Only pass the clean segment to your outbound campaign
5. Document the scrub date and results for compliance records

DNC Checker vs DNC Scrubber: Same Tool, Different Terms

You may see these terms used interchangeably: DNC checker, DNC scrubber, DNC lookup, DNC verification. They all refer to the same operation — checking a phone number or list against Do Not Call data and returning a clean or flagged result. The output shows which numbers were found on a list so you can exclude them.

What the DNC Checker Does Not Cover

The National DNC Registry covers the whole US. Some states also keep their own separate DNC lists. DNC Lookup includes six of them — Texas, Florida, Pennsylvania, Indiana, Colorado and Wyoming — and many other states merged their lists into the national registry. If you call heavily into a state with its own list that we do not cover, check that state’s rules; you may need its list directly.

Also, DNC rules govern telemarketing calls. They generally do not restrict calls made with prior express written consent, most calls to business numbers, or calls from political organizations, charities, and survey firms — but exemptions are narrow, so check with counsel. Using RealValidito does not register you with the National DNC Registry; keeping any registry access (SAN) the law requires is your responsibility.

Batch DNC Scrubbing

For large lists, use CSV upload. Upload files with up to 50,000 rows, and download the results: All data, Cleaned, TCPA Litigators, Federal DNC or State DNC. Empty rows are not counted.

For list intake (e.g., web form submissions), use the API to check each number at the point of capture — before it enters your CRM.