Area code 357 vs 559
357 and 559 are overlay codes: they cover the same ground in California, and a number in one is a local call to the other. 559 is the original, in service since 1998. 357 was added in 2025 because the first was filling up – that is what an overlay is for. Today 357 has 9 of 786 blocks assigned (1.1%) and 559 has 785 of 786 (99.9%), so a new number in the area now almost always comes from 357. 559 appears in the complaint data with 698 complaints in the window; 357 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
| 357 | 559 | |
|---|---|---|
| In service since | 2025 | 1998 |
| Region | California | California |
| Blocks assigned | 9 of 786 (1.1%) | 785 of 786 (99.9%) |
| Largest block holder | Onvoy 55.6% | AT&T 41% |
| Complaints, 28 Sep – 30 Oct 2026 | not in the data | 698 (#131) |
| Rate centers | 9 | 60 |
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 357 and 559?
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 357 and 559?
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 357 or 559?
Whichever has blocks left – currently 357, at 1.1% allocated against 99.9% for the other. Carriers draw from the code with free blocks, which is why the newer code spreads over time.
Is 357 or 559 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
- NANPA – CO Code Assignment Records, All States (utilized), file updated 11/01/2026, 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: 357 · 559. All codes in California: California area codes.