California Phone Number Lookup

(650) 337-3537

What are San Mateo County Area Codes?

The County of San Mateo is a county in the State of California. It has a population of over 700,000, and the county seat is Redwood City.

Area codes are the string of three-digit numeric codes that start North American telephone numbers. Area codes were instituted by the North American Numbering Plan (NANP) to depict the different numbering plan areas (NPAs). The NANP divides service territories under its purview into NPAs to ease long-distance communications and identify telephone calls’ origins and destinations. Area codes in San Mateo County are administered by the California Public Utility Commission (CPUC).

Three area codes currently cover San Mateo County. These are:

Area Code 650

Area code 650 is a telephone area code in the NANP for the San Francisco Bay Area. It split from area code 415 in 1997 and includes most of San Mateo County and parts of the neighboring counties. San Mateo County cities covered by this area code include Belmont, Daly City, Foster City, Menlo Park, Millbrae, Pacifica, Redwood City, San Bruno, and San Mateo.

Area Code 415

Area code 415 is a California telephone area code under the NANP. It is one of the original area codes introduced in 1947 and covers the San Francisco Bay Area, including parts of San Mateo County. Cities in San Mateo County under this area code are Brisbane and Daly City.

Area Code 628

Area code 628 is the telephone overlay code for the 415 numbering plan area in the NANP.

What are the Best Cell Phone Plans in San Mateo County?

Wireless telephone services have become the dominant form of telecommunication in San Mateo County. This was inferred from a 2018 National Health Interview Survey report on telephone service distribution in California. The report estimated that about 55.4% of adults (over 18 years) used only wireless telephone services while about 3.3% used landlines. Among the child population (under 18), the survey concluded that about 63.5% were wireless-only users and 1.8% used only landlines.

All major phone carriers are available in San Mateo County and offer reliable coverage of the area. Also available are numerous Mobile Virtual Network Operators (MVNOs) who also provide good services at lower rates, though more limited than the major carriers. In San Mateo County, AT&T claims the best service coverage, followed closely by Verizon, and then T-Mobile. Sprint covers the least area in the county but still offers decent services where available.

VoIP (VoIP over Internet Protocol) is an alternative to wireless telephony and landlines that has gained popularity over the recent past. VoIP provides telephony services using IP networks, mainly the internet, instead of radio waves and copper cables. This makes VoIP phone services more efficient and cheaper than traditional telephone services. VoIP providers in San Mateo County offer services for both business and personal uses.

What Are San Mateo County Phone Scams?

San Mateo County phone scams are fraudulent acts, committed using telephone services, aimed at stealing money and confidential information from county residents. These acts are committed using live calls, robocalls, and text messages. Suspicious phone number lookups, using phone number search applications, can retrieve information on the phone numbers associated with these scams.

The San Mateo County District Attorney enforces laws against consumer fraud in the county. Residents can submit consumer complaints to the D.A’s Office using the consumer complaint form. Completed complaint forms should be returned by email or delivered to the D.A’s Office at 400 County Center, 3rd floor, Redwood City, CA 94063. County residents can also file reports on scams with their local police departments or the San Mateo County Sheriff.

Common scams in San Mateo County include:

What are Law Enforcement Impersonation Scams?

In these scams, callers impersonate deputies of the San Mateo County Sheriff’s Office (SMCSO) to fraudulently solicit money or sensitive information from residents. These callers can spoof Caller IDs to display phone numbers of the SMCSO to deceive residents into believing their calls are legitimate. The callers inform their targets of fictitious cases against them for offenses such as missed jury duties, court dates, and unpaid tickets. They then demand payments from the targets to dismiss the cases and threaten them with arrest warrants to make them comply. Prepaid green dot cards and gift cards are the payment methods typically requested by these callers or they ask for residents’ financial details.

The SMCSO warns residents that its deputies do not contact residents to inform them about impending warrants. The Sheriff’s Office will neither demand payment by prepaid cards and gift cards nor ask for residents’ personal information to dismiss cases. Residents are advised to reject such requests and report the phone calls to their local police department or the San Mateo County Sheriff’s Office. Reverse phone number lookup services can provide information that indicates numbers displayed on Caller IDs may be spoofed.

What are PG&E Utility Scams?

Pacific Gas and Electric Company (PG&E) alerts customers to calls from scammers pretending to be employees of the company. These callers sometimes spoof Caller IDs to show official PG&E telephone numbers and make several claims to defraud residents. Some callers inform residents of overdue bills and threaten to disconnect services if immediate payments are not made. They insist on payment by prepaid debit cards, gift cards, and wire transfers or request the targets’ financial information. Other callers claim power shutdowns are imminent in the areas and ask for targets’ personal information to ascertain if they will be affected.

PG&E warns customers about these callers and reiterates that it will never ask for customers’ financial information over the phone. It will also never request payments through such channels and advises customers never to give out personal information or make payments to unknown persons. Utility companies are required by law to provide defaulting consumers with multiple written notices before disconnecting their services. Residents who receive such calls should hang up and contact PG&E on 1 (833) 500-7226 to make inquiries. Victims of these scams can file reports with their local police departments or the FTC.

What are Coronavirus Scams?

The San Mateo County District Attorney (SMCDA) warns residents and businesses to be alert for coronavirus-related scams. Scammers have exploited the uncertainties and anxieties associated with the pandemic to take people’s money and steal identities. Several variations of coronavirus scams exist such as;

  • Callers selling fake home test kits, cures, medications, vaccines, or offering unproven treatments for COVID-19.
  • Callers impersonating charitable organizations and soliciting donations for individuals, groups, and areas affected by COVID-19.
  • Callers impersonating health officials or contact tracers to steal residents’ identifying and financial information.

The SMCDA warns county residents to be wary of unknown callers requesting payments by wire transfer or prepaid cards or asking for their personal information. There are no approved vaccines and medications for COVID-19, so any caller who offers one is a scammer. Residents can verify the authenticity of charities and businesses soliciting donations from the Better Business Bureau before sending money. Residents who would like to report COVID-19 related scams should contact the District Attorney’s Office, call (650) 363-4651, or call their local police departments. Residents can also use reverse phone searches to verify the identities of such callers.

What are Census Survey Scams?

San Mateo County residents should be cautious of phone scams being perpetrated by persons impersonating employees of the Census Bureau. These scammers call and get their targets to participate in census surveys, providing various reasons for the surveys. During the survey, they obtain information that is used to commit financial and identity thefts against their targets.

The Census Bureau issues warnings to residents about these scams. They inform residents that their employees will not request sensitive information such as complete social security numbers or complete financial accounts information from residents. Employees of the Census Bureau will also not solicit money from residents. Residents who receive such calls and suspect fraudulent activities should contact their Regional Offices or the National Processing Center for verification and further instructions. Phone number searches can identify if these calls are legitimately from the Census Bureau.

What are Robocalls and Spam Calls?

Auto-dialed phone calls preset to deliver recorded messages are known as robocalls. Used to deliver messages directly to mass audiences on behalf of sales and political organizations, robocalls were developed with legitimate intentions. However, this ability to target mass audiences has seen robocalls co-opted by phone scammers. Consumers are used to receiving robocalls and let their guard when receiving them. This increases scammers’ chances of success. Also, phone numbers used to deliver robocalls are easily spoofed making it more attractive to scammers who desire to remain anonymous.

Below are actions you can take to address illegal robocalls:

  • Add your number to the National Do Not Call Registry. Numbers listed in the registry are restricted from receiving sales calls. If you still receive lots of unwanted calls afterward, these are likely scam calls.
  • Report illegal robocalls to the FTC online or by calling 1 (888) 382-1222.
  • Use call-blocking tools offered by network service carriers offer tools to identify and block spam calls. Consult your service provider on the accessibility of these tools.
  • Use call-blocking tools built into smartphones to block spam callers and robocalls.
  • End a phone call once you verify it is a robocall. Do not follow any prompts given, as doing so indicates that you are a live recipient and will set you up for more robocalls.
  • Use reverse phone number search free services to identify incoming spam calls and phone numbers used by robocalls.

The FTC also provides guidelines to consumers on blocking unwanted calls on its website.

How to Spot and Report San Mateo County Phone Scams?

It is practically impossible to totally evade phone scammers. Scammers target anyone, irrespective of age, gender, and race. Unsuspecting and uninformed persons make the easiest targets so information and awareness remain among the best means of spotting potential phone scams. When dealing with unknown callers, online services that run phone number searches answer questions like “who called?” and “who is this number registered to?”

You can identify that a phone call is most likely a scam if:

  • The caller, claiming to be law enforcement, threatens you with fine, arrest, deportation, and prosecution to get you to comply with their demands. Real law enforcement officers will not threaten residents over phone calls
  • Your confidential information is proactively solicited by the caller. No legitimate organization asks its customers to provide their information on phone calls not initiated by the customers.
  • You are asked to make payments for debts you are unaware of, by unconventional channels, such as wire transfer, gift card, and prepaid debit card. Legitimate organizations are not typically not concerned about your payment methods, and will not insist on such irregular means. Scammers favor these payment methods because funds sent through them are difficult to trace and retrieve.
  • You are informed of gifts or winnings in competitions you never entered but must pay fees to receive them. It is not possible to win prizes for competitions you did not enter, and if you must pay to receive a gift, it is a scam.

Tools that perform phone number lookups by name, number, and address are available for free or for nominal fees. Information retrieved by these tools can prove important when reporting scam calls. Victims of phone scams or residents who have received suspicious phone calls they suspected were scams can receive assistance from any of the following agencies:

San Mateo County District Attorney (SMCDA) - The SMCDA enforces consumer laws and receives complaints from residents to determine if violations of enforceable laws have occurred. Victims of scams and other fraudulent practices should return completed consumer complaints forms by email. Alternatively, they can deliver them to the D.A’s Office at 400 County Center, 3rd floor, Redwood City, CA 94063.

Local Law Enforcement Agencies - Residents who believe they have been victims of scams should contact the San Mateo County Sheriff on (605) 363-4911 or their local police departments.

National Consumers League (NCL) - The NCL is a non-profit consumer advocacy group that operates the Fraud Center to provide consumers with information and resources to combat scams.

Federal Trade Commission (FTC) - This is the federal agency that provides consumer protection against fraudulent and unfair trade practices. The FTC also provides instructions on call-blocking to defend against unwanted calls. It also established the National Do Not Call Registry to address unwanted calls from telemarketers and sales businesses. Report illegal robocalls and fraudulent acts to the FTC online or by calling 1 (888) 382-1222.

Federal Communications Commission (FCC) - This is the federal agency that regulates interstate and international communications. It also establishes policies to protect consumers from telephone scams and provides instructions on how to stop unwanted robocalls and avoid phone scams. Victims of illegal robocalls and phone scams can file complaints with the FCC.


Better Business Bureau (BBB) - The BBB provides information and resources to protect county residents from scammers masquerading as legitimate businesses and commercial organizations.