Area code 510

Area code 510 at a glance

Area code 510 is a geographic area code in California, in service since September 2, 1991, according to the North American Numbering Plan Administrator (NANPA). It is an overlay: 510 and 341 cover the same territory, so neighbors on the same street can have different area codes. It is in the Pacific time zone. The places with the most assigned exchanges include Hayward and Richmond.

Where 510 numbers are local

510 holds 3.6% of the 22,087 central office codes assigned in California, the 9th most of the state's 41 codes. 2 Census places could be matched to rate centers with 510 exchanges; the most populous are Hayward (158,000) and Richmond (115,000). For a storefront or service area inside 510, the place pages show which prefixes are rated local there.

Ten-digit and seven-digit dialing in 510

According to NANPA's dialing-plan data, local calls within 510 are dialed as 1 plus ten digits and toll calls as 1 plus ten digits. Ten-digit local dialing means the area code is part of how customers save and recognize your number, so print it in full everywhere.

Carriers with 510 numbers

32 carriers hold the 785 central office codes assigned in 510. Pacific Bell has the most, with 277 (35%). 514 of the codes (65%) are pooled, meaning the code holder shares blocks of 1,000 numbers with other carriers instead of using all 10,000 itself. Numbers can move between carriers through porting, so a code's holder tells you where the block started, not where every number lives now.

Where 510 numbers are rated

NANPA assigns each central office code to a rate center, the local calling area that decides whether a call is local or toll. 510 has codes in 13 rate centers. The table lists the rate centers with the most codes, with the matching Census place where the abbreviation could be matched.

510 code assignments over time

An area code has 800 possible central office codes that start with 2 through 9, a few of which are reserved (such as N11 service codes and 555). 785 are assigned in 510, 98% of 800. 18 were assigned in 2020 or later.

Getting a 510 number for your business

For $99 a month, Callata puts a team of up to 5 on one plan ($20 for each person after that): up to 3 local numbers, unlimited inbound calls, a pooled allowance of 1,500 outbound US and Canada minutes per user, browser and cell calling, voicemail transcription with urgency triage, recorded calls with AI summaries and business-hours routing, with E911 on every number.

If you already have a number in area code 510, porting it to Callata is free. Texting from a local number requires a one-time carrier registration (10DLC, $49), and the numbers available in any area code depend on carrier inventory when you choose them.

Optional AI agents (receptionist, sales, support or scheduler) can answer calls after hours or when nobody picks up, take messages, text, email and transfer to your team. They are billed from prepaid AI minutes at $0.25 per minute, identify themselves as AI, and may only place outbound calls to people who consented, between 8am and 9pm.