Which carrier owns 340 numbers?
11 holders appear in the 58 number blocks assigned in 340 of the 786 possible. Liberty holds the largest named share at 27.6%, ahead of T-Mobile at 13.8%. A further 53.4% sits with holders outside the national carriers, counted together: competitive local exchange carriers, VoIP providers and the resellers behind app-based numbers. These are blocks allocated by NANPA, not customers. Number portability means a block registered to one carrier can be full of numbers now served by another, so the share describes the registry, not the market. The top 6 holders shown account for 99.9% of assigned blocks. Blocks are allocated to rate centers; the largest in 340 are CHTAMSTTHS (42), ST CROIX (7) and CHNSTDSTCR (7).
Share of assigned number blocks
Of the 58 blocks assigned in 340 out of 786 possible; the 6 holders shown cover 99.9% of them. Each block is 10,000 consecutive numbers. Bars are scaled to the largest holder, not to 100%.
Why this is not “who your caller uses”
Number portability means a subscriber keeps their number when they change carrier, while the block stays registered to whoever originally received it. In a code that has been in service for decades, a large share of numbers are served by a carrier other than the registered holder. The table above is an accurate picture of the numbering registry and a poor proxy for market share.
Where the blocks sit
Blocks are allocated to rate centers – the billing geography, not the carrier. NANPA truncates their names to ten characters, and in large metros they are telephone zones rather than places, so we leave them unchanged rather than guessing.
Frequently asked
Which carrier owns 340 numbers?
No single one. The largest named holder of number blocks is Liberty with 27.6%, across 11 holders in total. And ownership of a block is not the same as who serves a given number: people keep their numbers when they switch carriers.
Can I tell someone's carrier from a 340 number?
Not from the area code, and not reliably from the first six digits either. Portability has been in place for two decades, so the block's registered holder is often not the current carrier. A number-level lookup is the only way, and that is what the tool on the area code page does.
What does “Other CLEC / VoIP” mean here?
It is not a company. It is every holder outside the national carriers added together – competitive local exchange carriers, VoIP providers and the wholesalers behind app-based and business numbers. In many codes it is the largest line in the table, which is itself the finding: numbering has moved away from the big carriers.
How many carriers have numbers in 340?
11 appear as block holders in the current NANPA records, and blocks are spread over 4 rate centers.
Sources
- NANPA – NPA Database (npa_report.csv), file date 11/01/2026, retrieved Nov 1, 2026
- NANPA – CO Code Assignment Records, All States (utilized), file updated 11/01/2026, retrieved Nov 1, 2026
More about this code: overview · local time · all carriers