Area code 257 vs 604
257 and 604 are overlay codes: they cover the same ground in British Columbia, and a number in one is a local call to the other. 604 is the original, in service since 1947. 257 was added in 2025 because the first was filling up – that is what an overlay is for. Today 257 has 21 of 800 blocks assigned (2.6%) and 604 has 781 of 800 (97.6%), so a new number in the area now almost always comes from 257. 604 appears in the complaint data with 375 complaints in the window; 257 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
| 257 | 604 | |
|---|---|---|
| In service since | 2025 | 1947 |
| Region | British Columbia | British Columbia |
| Blocks assigned | 21 of 800 (2.6%) | 781 of 800 (97.6%) |
| Largest block holder | Other CLEC / VoIP 33.3% | – |
| Complaints, 28 Sep – 30 Oct 2026 | not in the data | 375 (#261) |
| Rate centers | 16 | 45 |
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 257 and 604?
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 257 and 604?
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 257 or 604?
Whichever has blocks left – currently 257, at 2.6% allocated against 97.6% for the other. Carriers draw from the code with free blocks, which is why the newer code spreads over time.
Is 257 or 604 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: 257 · 604. All codes in British Columbia: British Columbia area codes.