A list of phone numbers is not a list of people you can reach. Numbers get disconnected, reassigned, ported from a landline to a mobile and back, and a large share of any compiled file is stale by the time it is used. Verifying a phone is three separate checks, and a fourth if you plan to call.
Line type
Every number belongs to a block assigned to a carrier as either wireline or wireless, and a growing share belong to VoIP providers. The block tells you the original type. It does not tell you the current type, because numbers are ported between carriers and between types constantly. A line-type check has to consult the number portability database, which records where each number lives today, rather than the original block assignment. Without it, a large share of "landlines" are actually mobiles and vice versa, and an SMS campaign or a dialer's compliance logic is built on sand.
Carrier
The same lookup returns the current carrier. That matters for deliverability of SMS, for identifying prepaid and VoIP numbers that behave differently, and for spotting the carriers whose numbers churn fastest.
Activity
A number can be a valid mobile on a real carrier and still be dead: disconnected, unassigned or dormant. Carrier-level activity signals indicate whether the number is currently in service and, in some cases, how recently it was active. A file that has been checked for activity is a file where the dials connect. This is the check most compiled lists skip because it costs money per number.
Name on phone
A live mobile is only useful if it belongs to the person you think it does. Carrier and licensed consumer data associate a subscriber name with a number. Matching that name to the owner on the deed, or the licensee on the roster, is how a phone gets attached to a record with confidence. We ship two cuts: a strict cut where the name on the phone matches the target exactly, and a wide cut that allows a household match. Dialers start with the strict file.
Scrubbing before the call
If the plan is to call or text, the verified numbers still need to be checked against the National Do Not Call Registry, the state lists that go beyond it, and the known litigator lists that identify numbers belonging to people who sue under telemarketing law. The scrub date should travel with the file, because a scrub is only valid for a period. We deliver the flags, not just the survivors, so your compliance team can see what was removed and why.
What to expect
We do not quote a match rate before running your file. The share of a file that resolves to a verified, active mobile with a name match depends on where the file came from and how old it is. The free match report runs a slice and tells you, per field, what came back.
Questions
What is a line type check?
A lookup against the number portability database that returns whether the number is currently wireless, wireline or VoIP, and which carrier serves it.
What match rate should I expect on a phone append?
It depends on the age and origin of your file. We run a slice and report it rather than quote a number.
Do I still need a DNC scrub if the numbers are verified?
Yes. Verification says the number is live; the scrub says whether you may call it.