The 909 area code that locals know from San Bernardino, Ontario, Rancho Cucamonga, and dozens of surrounding cities now shares its map with 840. The overlay keeps new numbers flowing without forcing anyone to surrender a long held 909 line but it also locks in ten digit (or 1 + ten digit) dialing for every call.
New 840 Area Code Overlay
Regulators layered 840 on top of 909 rather than splitting the region. Existing numbers stay the same; new lines may receive 840. Because two codes serve one geography, callers must dial the area code plus the seven digit number on all local calls.
Where the 909/840 Overlay Applies
Most of the Inland Empire and far eastern Los Angeles County, including:
- San Bernardino, Ontario, Rancho Cucamonga, Fontana, Redlands, Rialto
- Pomona, Claremont, Diamond Bar, Chino, Chino Hills, Upland, Montclair
- Big Bear Lake, Yucaipa, Highland and parts of Corona and Eastvale
Dialing Rules (Effective Now)
Landlines: Dial 1 + area code + phone number (11 digits total).
Mobile phones: Dial area code + phone number (10 digits) or 1 + area code + number either works.
Seven digit dialing no longer completes a call.
Permissive 10 digit dialing began July 25 2020; mandatory 10/11 digit dialing started January 23 2021.
Key Dates for the 840 Roll Out
| Date | Milestone |
|---|---|
| July 25 2020 | Optional 10 /11 digit dialing period begins |
| Jan 23 2021 | 10 /11 digit dialing becomes mandatory |
| Feb 23 2021 | First 840 numbers available for new service |
What Stays the Same
- Your 909 phone number doesn’t change.
- Local calling areas and pricing remain identical.
- Three digit services (911, 211, 311, etc.) still dial with three digits.
- Long distance rules and toll rates are unaffected.
Frequently Asked Questions
Why overlay instead of a geographic split?
Overlays avoid the cost and confusion of forcing businesses and residents to change existing numbers.
Will caller ID look odd?
No 840 simply signals a newer assignment within the same Inland Empire footprint.
Do mobile users have to dial “1”?
Most wireless carriers complete calls with either 10 or 11 digits; landlines generally require the leading “1.”
Does the overlay raise call charges?
No. Rate center boundaries and tariffs stay exactly the same.
Need Help?
Check the California Public Utilities Commission (CPUC) overlay page or NANPA site for official details. Managing high volume voice traffic? Our network engineers are on call 24 / 7 to help you update SIP trunks, E 911 records, and auto dialers.
