Common questions about US and Canada phone number validation, TCPA compliance, DNC registry screening, and the phone-validator.us service.
About Phone Validation
What does phone validation actually check?
Phone validation queries carrier databases in real time to determine: whether the number is valid and active, what line type it is (mobile, landline, VoIP, toll-free, prepaid), which carrier currently holds it, whether the number has been ported, and whether it is on the Federal Do Not Call list or flagged as a TCPA litigant.
Is phone validation the same as a reverse phone lookup?
No. Phone validation checks technical and compliance status — active/inactive, line type, carrier, DNC registration. It does not return the owner’s name or personal address. Phone Validator US provides validation only and returns no personal data.
What phone number formats are accepted?
Any format: (555) 123-4567, 555-123-4567, 5551234567, +15551234567, or with spaces. The validator normalises the input before querying. US and Canada (+1) numbers are supported.
What line types can you detect?
Mobile, Landline, VoIP, Toll-Free, Prepaid, and Unknown. Knowing the line type is critical for TCPA compliance — autodialed calls and texts to mobile numbers require prior express written consent, with different rules applying to landlines.
TCPA & DNC Compliance
What is TCPA and why does it matter for phone validation?
The Telephone Consumer Protection Act (TCPA) restricts unsolicited autodialed calls, pre-recorded messages, and texts to mobile phones without prior express written consent. Violations carry fines of $500–$1,500 per call. Phone validation identifies mobile numbers before dialing and flags DNC registrations — both essential inputs to a TCPA-compliant calling workflow.
Does the DNC check cover all US state DNC lists?
We check the Federal Do Not Call Registry maintained by the FTC. Individual state DNC registries vary and are not included. For regulated industries — insurance, mortgage, debt collection — consult your compliance counsel about state-specific requirements.
What is a TCPA litigant flag?
A TCPA litigant flag identifies a number associated with a known TCPA plaintiff — individuals who file lawsuits against businesses that contact them. Calling a litigant without correct consent on file carries significantly higher enforcement risk. The flag appears in the validation response as tcpa_litigant: true/false.
Does phone validation require consent from the number owner?
No. Phone validation is a carrier database query — it does not dial, contact, or send any message to the number. No consent from the owner is required to validate a phone number.
Bulk Processing & API
How many numbers can I validate at once?
Up to 50,000 phone numbers per CSV upload. Results are returned as a downloadable file with validation data appended to each row. For higher volumes, use the REST API in a processing loop.
What programming languages does the API support?
The API is a standard JSON REST endpoint — any language that can make an HTTPS POST request works. Documented code examples are available for PHP, Python, JavaScript (Node.js), Java, .NET (C#), Ruby, and Go.
How fast is the API response?
Under 1 second for a single lookup. The service operates at a 99.9% uptime SLA. For real-time form validation, the latency is low enough to run a synchronous check before the lead record is saved.
Account & Credits
How many free credits do I get at signup?
Every new account starts with 1,000 free validation credits. No credit card required. Credits apply to single lookups, batch CSV processing, and API calls.
Do credits expire?
Never. Credits stay in your account indefinitely until used. No monthly fees, no subscription, no expiry. Pure pay-as-you-go.
Is my phone number data stored?
No. Numbers submitted for validation are processed in real time and not stored or retained beyond the transaction. We do not build a database of validated numbers.
Still have questions?
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