The fastest way to identify an unknown caller
If you received a call from an unknown number, your phone itself is usually the first place to look. On both iPhone and Android, your call history shows the number that called you — tap or click it to see if your phone has already identified it as spam, a business, or a contact you know. If the number is not labeled, you can search it directly in Google or another search engine by typing the full number in quotes, like "555-123-4567". Many spam and business numbers appear in public directories or complaint databases within seconds.
If a web search does not work, try a reverse phone lookup service. These sites let you enter a phone number and see what information is publicly available about it — usually the caller's name, location, and whether others have reported it as spam. Common free options include TrueCaller, WhitePages, and Spokeo, though some charge for detailed reports. Enter the number exactly as it appeared on your phone, including the area code.
If the call came from a business or government agency, check your email and mail for recent statements or notices that might list a callback number. Many companies call from numbers different from the ones printed on your bills, so matching the caller's message to a recent transaction can confirm who they were.
Key Takeaways
- Your phone's call history often shows whether it has already identified the caller as spam, a business, or a known contact.
- Searching the number in Google using quotes around it — like "555-123-4567" — usually returns results if it is a business or widely reported spam number.
- Reverse phone lookup services like TrueCaller and WhitePages show public information tied to a number, including whether others have reported it as spam.
- If you do not recognize a number, do not call it back immediately; wait to see if the caller leaves a voicemail or if a search identifies them first.
Why your phone may already know who called
Modern phones use caller identification databases that update constantly. When a call comes in, your phone checks the number against these databases and labels it if there is a match. On iPhone, this appears as "Spam Risk" or the business name. On Android, Google's Call Screen feature and carrier-provided identification work similarly. These systems are not perfect — they miss small businesses and individuals — but they catch most major companies and known spam numbers.
If your phone did not identify the number, it means it is either a private individual, a very small business, a spoofed number (one that has been faked to look like something else), or a number too new to be in the database yet. In these cases, a manual search is your next step.
How to search for a number online
Open Google and type the number in quotation marks exactly as it appeared on your phone. For example, if the number was 555-123-4567, search for "555-123-4567". Google will return any web pages that mention that exact number — usually complaint forums, business listings, or public records. Read the results carefully: if multiple people have posted about the number complaining it is spam, that is a strong signal. If it appears on a business website or government agency page, you have found your answer.
If Google does not return useful results, try searching without quotes, or search the number along with your city name. Some local businesses and services only appear in regional results. You can also try searching the number plus the word "scam" to see if it has been reported as fraudulent.
Be cautious about clicking links from unknown sources when searching. Stick to well-known websites like government agencies, major businesses, or established complaint databases. If a result looks suspicious, skip it.
Using reverse phone lookup services
Reverse phone lookup sites are designed specifically to find information about phone numbers. TrueCaller is free and shows whether a number is spam, a business, or a contact. WhitePages and Spokeo offer free basic searches and charge for more detailed reports. To use them, visit the site, enter the phone number in the search box, and wait for results.
These services pull from public records, business directories, and user reports. They often show the caller's name, city, and whether the number has been flagged as spam by other users. Some services also show whether a number is associated with a known scam or robocall pattern. The information is usually accurate for businesses and established phone numbers, though it may be outdated or missing for newer numbers or individuals who have opted out of public listings.
Free reverse lookup services have limits — they may show less detail than paid versions, or they may require you to create an account. Paid services typically cost between $5 and $20 for a single detailed report. Before paying, try the free options first, since they often provide enough information to identify whether a number is spam or legitimate.
What to do if the number is spoofed or masked
Some callers use technology to hide their real number or make it appear as though they are calling from a different number. This is called spoofing. If you search a number and find it belongs to a major company or government agency, but you did not contact them and the call seemed suspicious, the number was likely spoofed. Scammers often fake numbers from banks, the IRS, or utility companies to trick people into giving out personal information.
If you suspect spoofing, do not return the call. Instead, contact the company or agency directly using a number you find yourself — call the main customer service line on their official website or your bill. Tell them about the call and ask if they tried to reach you. Legitimate companies can confirm whether the call came from them. If it did not, report the spoofed number to the Federal Trade Commission at ReportFraud.ftc.gov or to your phone carrier.
How to block and report unknown numbers
Once you have identified a number as spam or unwanted, block it directly from your phone. On iPhone, open the call history, tap the number, and select "Block this Caller". On Android, tap the number in your call log, then tap the three-dot menu and select "Block number". Blocked callers can still leave voicemails, but their calls will not ring through to you.
Report the number to your phone carrier and to the Federal Trade Commission. Carriers use reports to improve their spam-blocking systems. The FTC collects reports at ReportFraud.ftc.gov and shares patterns with law enforcement. If the call was a scam attempt, reporting it helps protect others from the same number. Include details about what the caller said and when they called.
When you should not call a number back
If you do not recognize a number and a search does not identify it, do not call it back immediately. Scammers sometimes use techniques that charge you money for calling certain numbers, or they use your return call to confirm your number is active and worth targeting again. Wait to see if the caller leaves a voicemail. A legitimate caller will usually leave a message explaining who they are and why they called.
If you think the call might be important — for example, from a doctor's office or a delivery service — search the number first or wait for a follow-up call. Legitimate businesses will call again or send you a message with more information. If the caller was real, they will try to reach you through a method you recognize.
Frequently Asked Questions
Can I find out who called me if they blocked their number?
No. When someone blocks their number, it shows up as "Unknown" or "Private" on your phone, and there is no way to see the actual number. You cannot search or look up a number you do not have. Your only option is to wait for a voicemail or a follow-up contact that identifies the caller.
Is it safe to use reverse phone lookup websites?
Free reverse lookup services are generally safe — they pull from public records and do not ask for sensitive information. Avoid sites that ask for payment upfront or request personal details beyond the phone number. Stick to well-known services like TrueCaller, WhitePages, and Spokeo. Read reviews before using a service you have not heard of.
What if the number shows up as a business I do not recognize?
Search the business name online to confirm it is real. Many scammers use fake business names that sound official. If the business is real but you did not contact them, they may have called the wrong number, or your number may have been sold to a marketing company. You can ask them to remove your number from their list or block the number.
Can I report a number to my phone carrier?
Yes. Contact your carrier's customer service and report the number as spam or unwanted. Most carriers have online forms or phone lines for spam reports. Your report helps the carrier improve its spam-blocking system. You can also report the number to the Federal Trade Commission at ReportFraud.ftc.gov.
What should I do if I think the call was a scam?
Do not send money or give out personal information. Report the number to the Federal Trade Commission at ReportFraud.ftc.gov and to your phone carrier. If the scammer has your financial information, contact your bank or credit card company right away. You can also file a report with your local police department, though they may not investigate individual scam calls.