Glossary
What is a ported number?
A ported number is a phone number that moved from one carrier to another while keeping the same digits. After a port, the area code and prefix still point to the original carrier, so only a live lookup shows who holds the number now.
The terms behind number porting
| Ported number | A phone number that was moved from one carrier to another while the subscriber kept the same digits. |
| Number porting | The process of moving a number between carriers. In the US it is required by the FCC's local number portability rules. |
| LNP | Local Number Portability. The FCC rules and the shared industry database that let a number keep working after it moves to a new carrier. |
| Original carrier | The company that was first assigned the number block (NPA-NXX) the number belongs to. This is what prefix tables show. |
| Current carrier | The company that holds the number today. After a port this is different from the original carrier, and only a live lookup shows it. |
How a number gets ported
- The subscriber signs up with a new carrier and asks to keep their existing number.
- The new carrier sends a port request to the old carrier with the account details.
- Once the old carrier releases the number, the shared portability database is updated so calls and texts route to the new carrier.
- The digits stay the same. Only the carrier, and sometimes the line type, changes.
Prefix data vs. a live carrier lookup
| Prefix (NPA-NXX) data | Live carrier lookup | |
|---|---|---|
| What it tells you | Who was first assigned the number block | Who holds the number now |
| Accurate after a port | No. It still shows the original carrier | Yes. It reflects the move |
| Line type after a port | Can be wrong, for example a landline number ported to a cell phone | Shows the line type the number has now |
| Where it comes from | Public numbering assignment data | Carrier data queried per number |
Want to see who was first given a prefix? Try the free phone number prefix lookup, then compare it to a live carrier lookup.
Why ported numbers matter on a lead list
- Line type: a number that started as a landline may be a cell phone or VoIP line today, which changes how you call or text it.
- Carrier routing: anything sorted by carrier from prefix data puts ported numbers in the wrong group.
- Not a compliance check: knowing a number was ported says nothing about Do Not Call status or consent.
What TrueSearch returns, and does not
| Valid or dead (disconnected / not assigned) | Yes, every number |
| Line type: mobile, landline, VoIP, toll-free | Yes, every number |
| Carrier name | Yes, every number |
| Bulk upload (CSV or Excel) | Yes, results in about 30 seconds per 1,000 numbers |
| REST API | Yes (JSON, one API key) |
| Claude / ChatGPT / Cursor connector (MCP) | Yes |
| National or state Do Not Call check | No, not yet |
| Known TCPA litigator check | No, not yet |
| FCC Reassigned Numbers Database check | No |
| Starting price | $97/month for 5,000 numbers, 7-day free trial |
| One-off list | $20 per 1,000 numbers, no subscription |
Upload a CSV or Excel file. Every number comes back valid or dead, mobile, landline, VoIP or toll-free, with the carrier it is on now.
Starter: $97/month for 5,000 numbers after the 7-day trial. Cancel anytime.
Questions
What is a ported number?
A ported number is a phone number that moved from one carrier to another while keeping the same digits, for example when someone switches wireless carriers and keeps their number. The number keeps working; only the company behind it changes.
Is number porting legal in the US?
Yes. The FCC requires local number portability, so consumers and businesses can keep their number when they switch carriers, as long as they stay in the same area. Wireless-to-wireless, landline-to-wireless and other moves are covered. See fcc.gov for the rules.
Can a landline number be ported to a cell phone?
Yes. A number that started as a landline can be ported to a wireless carrier or a VoIP provider. That is one reason the area code and prefix alone cannot tell you whether a number is a landline or a cell phone today.
How do I find the current carrier of a ported number?
Run a live carrier lookup. Prefix tables only show who was first given the number block. TrueSearch reads live carrier data, so a ported number shows the carrier it is on now. You can check one number free.
Does TrueSearch tell me if a number was ported?
TrueSearch shows the current carrier and line type. If that differs from the original carrier for the prefix, the number has moved, but TrueSearch does not return a separate ported yes/no field or the date of the port.
Why does porting matter for a lead list?
If you sort or route leads by carrier or line type using prefix data, ported numbers end up in the wrong bucket, for example a cell phone tagged as a landline. Checking each number live keeps the line type and carrier current.
Does TrueSearch check Do Not Call status?
No. TrueSearch checks validity, line type and carrier only. For Do Not Call status, use the National Do Not Call Registry at donotcall.gov.
Related: what is phone line type?, what is an HLR lookup?, what is a VoIP number?, free carrier lookup and landline checker.
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This guide is general information, not legal advice. TrueSearch for Business checks validity, line type and carrier from licensed telecom data. It does not check the National Do Not Call Registry, state DNC lists or the FCC Reassigned Numbers Database. Not a consumer reporting agency; not for FCRA purposes.