Area code 437 vs 942
437 and 942 are overlay codes: they cover the same ground in Ontario, and a number in one is a local call to the other. 437 is the original, in service since 2013. 942 was added in 2025 because the first was filling up – that is what an overlay is for. Today 437 has 563 of 800 blocks assigned (70.4%) and 942 has 57 of 800 (7.1%), so a new number in the area now almost always comes from 942. 437 appears in the complaint data with 115 complaints in the window; 942 does not appear at all, which is what you would expect of a code that is barely used so far. Neither code is better or safer than the other. They are the same geography, the same carriers and the same dialing rules; the difference is only how long each has existed and how full it is.
Side by side
| 437 | 942 | |
|---|---|---|
| In service since | 2013 | 2025 |
| Region | Ontario | Ontario |
| Blocks assigned | 563 of 800 (70.4%) | 57 of 800 (7.1%) |
| Largest block holder | – | Other CLEC / VoIP 5.3% |
| Complaints, 28 Sep – 30 Oct 2026 | 115 (#373) | not in the data |
| Rate centers | 1 | 1 |
Block share is allocation by the numbering administrator, not subscribers. Complaint counts cover 28 Sep – 30 Oct 2026 and measure how often each code is spoofed on caller ID.
Frequently asked
What is the difference between area codes 437 and 942?
None geographically – they overlay the same area, so the difference is age and how many numbers are left.
Do I need to dial the area code between 437 and 942?
Yes. Overlay areas use ten-digit dialing for local calls, including between the two codes. Seven digits reaches a recording.
Will a new number be 437 or 942?
Whichever has blocks left – currently 942, at 7.1% allocated against 70.4% for the other. Carriers draw from the code with free blocks, which is why the newer code spreads over time.
Is 437 or 942 more likely to be a spam call?
The data does not support a comparison: only one of the two appears in the complaint window.
Sources
- NANPA – NPA Database (npa_report.csv), file date 11/01/2026, retrieved Nov 1, 2026
- Canadian Numbering Administrator – CO Code Status, data date 2026-10-31, retrieved Nov 1, 2026
- FTC – Do Not Call Reported Calls Data, 28 Sep – 30 Oct 2026, retrieved Nov 1, 2026
Each code on its own: 437 · 942. All codes in Ontario: Ontario area codes.