The fastest way to identify an unknown caller
If you have a missed call or an unknown number on your phone bill, the quickest path is to search the number itself in a search engine or a reverse phone lookup service. Type the number into Google, Bing, or DuckDuckGo exactly as it appears — with or without dashes — and you will often see if others have reported it as spam, a business, or a scam. If that returns nothing useful, a reverse lookup tool like TrueCaller, WhitePages, or Spokeo can show you the name and address associated with the number, though some information requires a paid account.
Your phone's built-in tools also work. On iPhone, open the Phone app, find the number in your recent calls or voicemail, and hold down on it — you will see options to block it or report it as spam. On Android, open the Phone app, tap the number, and scroll down to see if Google has already identified it. Both systems learn from millions of user reports, so a number flagged by many people will show a warning label.
If the call came through your landline or a business phone system, check your call log or phone bill. Most providers let you view recent calls online through your account, and some show the caller ID name that was transmitted with the call — this is often more reliable than a reverse lookup because it came directly from the caller's phone company.
Key Takeaways
- Search the phone number directly in Google or another search engine first — this is free and often shows whether others have reported it as spam or identified it as a business.
- Your phone's built-in caller ID system (Google on Android, Apple on iPhone) flags numbers that many users have reported as spam or scams.
- Reverse lookup services like TrueCaller or WhitePages show the name and address tied to a number, though detailed information often requires payment.
- Check your phone bill or call log through your provider's website — the caller ID name transmitted with the call is usually more accurate than a reverse lookup.
- If a number calls repeatedly and you do not recognize it, block it directly from your phone rather than answering or calling back.
Using your phone's built-in identification features
Both iPhone and Android have spam detection built in, and it improves as more people report numbers. On iPhone, go to Settings, then Phone, then Silence Unknown Callers — this sends calls from numbers not in your contacts to voicemail, and you can still see them in the recent calls list. On Android, open the Phone app, tap the three-line menu, go to Settings, then Spam and Abuse, and turn on "Filter spam calls" — Google will flag suspected spam before it rings.
When a number does call through, both systems show what they know. On iPhone, the lock screen or call screen displays the name if it is in your contacts or if Apple's database recognizes it. On Android, the Phone app shows a label like "Spam Risk" or the business name if Google has identified it. These identifications come from millions of user reports, so they are usually accurate for common spam or well-known businesses.
If you want to report a number yourself, both systems let you do it. On iPhone, end the call, find it in your recent calls, swipe left, tap the information icon, scroll down, and tap "Report as Junk." On Android, open the Phone app, find the number, tap the three dots, and select "Report as spam." Your report goes into a database that helps identify the number for other users.
Reverse phone lookup services and how they work
A reverse phone lookup searches a database of phone numbers and returns the name, address, and sometimes other details tied to that number. Services like TrueCaller, WhitePages, Spokeo, and BeenVerified maintain these databases by collecting information from public records, phone directories, and user reports. When you enter a number, the service searches its database and shows you what it has on file.
Free reverse lookups usually show basic information — the name and city associated with the number. Paid accounts unlock more details like the full address, email, age, and sometimes social media profiles. The accuracy depends on how recent the database is and whether the number is listed in public records. Landlines and business numbers are usually easier to identify than cell phones, because cell phone carriers do not publish directories the way they used to.
Keep in mind that reverse lookup databases are not always current. A number might be listed under a previous owner's name, or a business might have changed hands and the database has not updated. If a reverse lookup shows a name you do not recognize, search that name plus the city to see if it is a real person or business, or search the number itself in Google to see if others have reported it.
Checking your phone bill and call logs
Your phone provider keeps a record of every call you receive, and you can view this history through your account online. Log into your provider's website or app — Verizon, AT&T, T-Mobile, and most others have a section called "Call History," "Recent Calls," or "Usage Details." You will see the date, time, and duration of each call, and most providers also show the caller ID name that was transmitted with the call.
The caller ID name is important because it comes directly from the caller's phone company, not from a third-party database. If a business called you, their name usually appears here. If a scammer spoofed a number (made it look like it came from somewhere else), the caller ID name might be fake, but it is still the name they wanted you to see. This information can help you figure out whether the call was legitimate or a scam attempt.
If you need to go back further than your provider shows online — some only display the last 30 to 90 days — call your provider's customer service and ask for a detailed bill. They can usually send you a longer history by email or mail. This is especially useful if you are trying to track a pattern of calls from the same number over weeks or months.
How to tell if a number is spam or a scam
Spam and scam calls have patterns you can recognize. Spam is usually a recorded message trying to sell you something — a credit card offer, a car warranty, a loan. Scams pretend to be from a bank, the IRS, a utility company, or tech support, and they ask you to confirm personal information, send money, or click a link. Neither will identify themselves clearly when you answer, and both often use spoofed numbers that look local or official.
If you search a number in Google and see multiple reports saying "spam," "scam," or "do not answer," that is a strong signal. Sites like RoboKiller, the FTC's complaint database, and Reddit's r/scams community collect reports from real people. If dozens of people say a number called them with the same message, it is almost certainly spam or a scam. Do not call the number back, because that confirms your number is active and may lead to more calls.
Legitimate businesses and government agencies do not call asking you to confirm your Social Security number, bank account, or passwords. If a call asks for that information, it is a scam, regardless of what caller ID says. Hang up and call the organization directly using a number from their official website or your statement — do not use a number the caller gave you.
What to do if you cannot identify the caller
If you have searched the number, checked your phone's identification system, run a reverse lookup, and found nothing, the call was probably from someone using a spoofed number or a burner phone. Spoofing is when someone makes a call appear to come from a different number than it actually does — scammers do this to make their calls look local or official. A burner phone is a cheap prepaid phone used for a single purpose and then discarded, so there is no permanent record tied to it.
In both cases, you have limited options for identifying the caller. If the call came with a voicemail, listen to it — the message itself often reveals whether it is spam, a scam, or a legitimate business trying to reach you. If there was no message and the number never calls back, it was probably a wrong number or a one-time spam attempt. Block the number in your phone settings so you do not hear from it again.
If the same number keeps calling and you cannot identify it, document the dates and times, then report it to the FTC at ReportFraud.ftc.gov or to your state's attorney general. If it is a scam, your report helps law enforcement track patterns. If it is harassment, you may have grounds to contact your phone provider or local police, though they usually require a pattern of calls over time.
Protecting yourself from unknown callers
The best defense is to not answer calls from numbers you do not recognize. Let them go to voicemail — if it is important, the caller will leave a message and you can call them back using a number you verify yourself. If you do answer and the caller asks for personal information, money, or access to your computer, hang up when ready. No legitimate organization calls asking for passwords, Social Security numbers, or banking details.
Enable call filtering on your phone. On iPhone, use "Silence Unknown Callers" so unknown numbers go straight to voicemail. On Android, turn on "Filter spam calls" in the Phone app settings. Both systems are not perfect, but they catch most automated spam and scam calls. You can also read a dedicated call-blocking app like RoboKiller or Nomorobo, which use machine learning to identify spam patterns and block calls before they reach you.
If you are on the National Do Not Call Registry, telemarketers are supposed to stop calling you, but scammers ignore it. You can register at DoNotCall.gov, but this mainly stops legitimate telemarketing calls, not scams. The real protection is the combination of call filtering, not answering unknown numbers, and reporting spam when you see it — the more people report a number, the faster it gets flagged for everyone else.
Frequently Asked Questions
Can I find out who called me if they blocked their number?
If a call came through as "Unknown" or "Blocked," the caller deliberately hid their number, and there is no way to identify them through normal means. Your phone bill will show a call occurred but will not display the number. If the calls are repeated and unwanted, report them to your provider and consider filing a police report for harassment.
Is it safe to call back a number I do not recognize?
Calling back an unknown number can confirm to scammers that your number is active, leading to more calls. If you think the call might be legitimate, search the number first or call the organization directly using a number from their official website. Never call back a number that left a voicemail asking you to confirm personal information.
Why does my caller ID sometimes show a name I do not recognize?
Caller ID names come from your phone company's database or from the caller's phone company. If a business changed ownership or a person moved, the database may not have updated. If the name looks suspicious or the call is asking for money or information, it is likely spoofed — the caller made it look like it came from somewhere else.
Do reverse phone lookup services cost money?
Basic reverse lookups are free on services like TrueCaller and WhitePages — they show the name and city associated with a number. Detailed information like full address, email, and background reports usually requires a paid subscription. Searching the number in Google first is free and often shows whether others have reported it as spam.
What should I do if a number keeps calling me?
Block the number directly in your phone settings. On iPhone, find the number in your recent calls, tap the information icon, and select "Block this Caller." On Android, open the Phone app, find the number, tap the three dots, and select "Block number." If the calls continue from different numbers or feel like harassment, report them to the FTC or your local police.