Area code 340: US Virgin Islands
What is area code 340?
Area code 340 is a US territory area code for the US Virgin Islands, on Atlantic Standard Time. It has 58 prefixes in service across 4 rate centers, the largest being CHTAMSTTHS, St Croix and CHNSTDSTCR. NANPA lists no overlay code for it. Local calls there take 7 digits. The code never shows a line is in service.
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See the phone add-onArea code 340 facts
| Location | US Virgin Islands, United States |
|---|---|
| Time zone | Atlantic Standard Time |
| Overlays | None |
| Split from | 809 |
| In service since | June 1, 1997 |
| Local calls | 7 digits; toll calls 1 + 10 digits |
| Carrier | Not shown. An area code is where a number was issued; numbers port between carriers. Check line type |
In short: 340 is US Virgin Islands (Atlantic Standard Time). Format checks here are free and run in your browser; the current carrier and line type need a live lookup. Bulk phone number validator · Pro + Phone plan
Local time in area code 340
America/St_Thomas
Prefixes in service
58 of 792 possible
4 rate centers
Which cities and towns use area code 340?
NANPA records each prefix against a rate center, the local billing area a number belongs to, usually named after its main town. These are the 340 rate centers with the most prefixes in service.
| Rate center | Prefixes |
|---|---|
| CHTAMSTTHS | 42 |
| St Croix | 7 |
| CHNSTDSTCR | 7 |
| FRKSTDSTCR | 2 |
Source: NANPA central office code assignments, file dated 10/17/2026. Each prefix holds up to 10,000 numbers.
How do I dial a 340 number?
NANPA's dialling plan for 340: local calls inside the code take 7 digits, toll calls 1 + 10 digits. From another area code, dial 1 first. From abroad, use +1. The examples use 555-0147, from a range reserved for fictional numbers.
| Local call inside 340 | 555-0147 |
|---|---|
| From another US or Canadian area code | 1-340-555-0147 |
| From outside North America | +1 340 555 0147 |
| E.164, for CRMs and SMS tools | +13405550147 |
When did area code 340 start?
Area code 340 went into service on June 1, 1997, split from 809. It has no overlay, so every number in its area still starts with it.
Tools for 340 numbers
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- Area code time zone
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- NPA-NXX lookup
Rate center and state for one prefix, a level below the area code.
- TCPA calling hours checker
Whether it's inside the federal 8 a.m. to 9 p.m. calling window there now.
Next step
A 340 number tells you where it was issued, not what it is now.
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Area code 340 questions
- What state or territory is area code 340?
- Area code 340 is in the US Virgin Islands, United States. Its largest rate centers by number of prefixes are CHTAMSTTHS, St Croix, CHNSTDSTCR and FRKSTDSTCR.
- What time zone is area code 340 in?
- Atlantic Standard Time.
- Does area code 340 have an overlay?
- Not as of NANPA's file dated 10/16/2026. Every number in its area uses 340.
- When did area code 340 start?
- Area code 340 went into service on June 1, 1997, split from 809.
- Is a 340 number a cell phone or a landline?
- The area code can't tell you. In the US and Canada mobiles, landlines and VoIP lines share area codes and prefixes, and numbers move between carriers and line types. Only a live line-type lookup answers it for one number.
- How many phone numbers does area code 340 have?
- 58 of its 792 possible prefixes are in service, and each prefix holds up to 10,000 numbers. That counts prefixes assigned to carriers, not numbers in use.
- Does a valid format mean a 340 number is in service?
- No. A format check only says the digits fit the North American Numbering Plan and that 340 is an assigned code. It cannot tell whether the number is connected, who answers it or which carrier serves it today, because numbers are reassigned and ported. A live carrier lookup reports the current carrier and line type, but even that is not proof someone answers.
- Can I check a list of 340 numbers for free?
- Yes. Paste them in the list tab above or upload a CSV to the bulk phone number validator: format, E.164, country and the numbering-plan line type are free for every row, with no account. Live carrier and line-type lookups come with Pro + Phone at $49.99/mo (5,000 a month).
More area codes
340 is the only area code in US Virgin Islands. Browse every area code by state and province on the area code index.
Sources
Location, overlays, in-service date and dialling plan: NANPA NPA database, file dated 10/16/2026. Prefixes and rate centers: NANPA central office code assignments, 10/17/2026. Time zones mapped to the IANA time zone database. By the SimpleVerifier Team; how we build these pages.