Area code 343 – Ontario
343 has served Ontario since 2010, split from 613. 644 of its 800 number blocks are allocated (80%). No carrier dominates: Other CLEC / VoIP 31.4%. It shares its geography with overlay codes 613, 753, so local calls take all ten digits. Spam complaints are comparatively rare: 188 in the 33 days to 30 October 2026, 349th of the 422 codes with five or more complaints. Most of its numbers are in Ottawa-Hull, Kingston, Cornwall.
- Province
- Ontario
- In service since
- 2010
- Time zone
- Eastern
Who holds 343 number blocks
Share of the 644 assigned NXX blocks (80.5% of the 786 possible), across 1 carriers. This is share of number blocks, not of subscribers.
- Other CLEC / VoIP31.4%
Spam complaints naming 343
FTC Do Not Call complaints where the caller ID was a 343 number, 28 Sep – 30 Oct 2026 (33 days). Caller IDs on spam calls are frequently spoofed, so these are complaints about the code, not calls proven to originate in it.
Rate centers in 343
NANPA allocates number blocks to rate centers and records their names abbreviated to ten characters, so these are NANPA's codes rather than place names – CHAMPAURBN is Champaign-Urbana, NWYRCYZN01 is a New York City zone. We show them unchanged instead of guessing at the full names. Showing the largest 5 of 116.
Timeline
- 2010 343 goes into service, split from or overlaid on 613.
More about 343
Separate pages for the questions that need their own answer: what time it is there, what the complaint data says, who holds the number blocks, and how the code compares with the one it shares its area with.
Frequently asked about 343
Where is area code 343?
Ontario. It covers the same area as 343/613/753.
Is a call from 343 a scam?
Not by itself. 343 drew 188 FTC complaints in the 33 days to 30 October 2026, 349th of 422 ranked codes – mid-pack or lower. Spam callers spoof caller IDs, so the only useful check is the full number.
Which carrier owns 343 numbers?
Other CLEC / VoIP holds the largest share of assigned number blocks at 31.4%. This is share of number blocks, not of subscribers – people keep their numbers when they switch carriers.
Do I need to dial 10 digits in 343?
Yes – ten digits for local calls in 343, because it shares its area with another code.
Sources and verification
- 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
- FTC – Do Not Call Reported Calls Data, 25 daily files 28 Sep – 30 Oct 2026, retrieved Nov 1, 2026
NANPA dialing note for this code: “10D”. Reviewed by the data desk. Spotted an error? Request a correction.