Caller ID is the name and number displayed when you receive a call. Your caller ID shows up when you call someone else.
There’s an important distinction, though — numbers you’ve saved in your contacts aren’t the same. We’re strictly talking about what appears when an unknown number calls you (or when you call someone who doesn’t have your number saved).
It’s more common on landlines, but we’re seeing it on mobile devices too. While it doesn’t always work on cell phones, it’s helpful to have an idea of who’s calling.
However, caller ID isn’t always accurate. Businesses and individuals alike can use number spoofing to make themselves appear as someone else.
Does that mean you shouldn’t trust it? Let’s find out.
How does caller ID work?
- Someone places a call: The caller’s phone transmits their number to the recipient’s phone provider using CLID (Caller Line Identification).
- The provider searches its database: Some phone companies have their own data sets, but most also search CNAM (Caller ID Name) lists to identify the caller.
- Caller ID appears: If there’s a match, it’ll show up on your phone.
This process relies on large databases of names and numbers. Large data sets like these are notorious for being outdated and inaccurate.
On top of that, CNAM databases aren’t universal. There are multiple CNAM databases in the United States and around the world, all maintained by different entities.
So, it’s entirely possible you’ll see the wrong name on your phone.
Despite that, it can still be a helpful tool for preparing yourself, deciding how you want to answer, and screening calls. Plus, it’s the best method we have to work with for identifying unknown callers.
How to find caller ID on your phone
Modern landline phones have a screen that displays caller information when someone calls you. In most cases, it’s set up by default. You shouldn’t have to configure anything for it to work.
If you want to know what it looks like when you call someone, the best way to find out is by calling another phone.
Many carriers also let you edit caller ID information in your account settings. You can always call customer service and ask them to update it for you too. However, that doesn’t always mean the correct information will show up when you call.
It takes time for your new caller ID to propagate across all the databases. Some people may see your new information, others may see the old.
For businesses, caller ID is crucial. It helps maintain trust with customers, making them more likely to answer. This open communication makes everything run smoother all around. It goes the other way too. They can connect their customer relationship management (CRM) software (which houses lead and customer data) to their phone system, letting them see which customer they’re about to talk to.
When done well, they’ll also be able to see other information, like previous purchases and who they talked to last time.
Finding caller ID for unknown numbers
What happens when caller ID doesn’t work and all you see is a random number? You can do a reverse phone lookup online using a free site like BeenVerified or Whitepages. A simple Google search can also yield free results — especially if that number is commonly associated with spam calls or a business.
If you really want to be proactive about identifying numbers and blocking unwanted calls, you can use an app like TrueCaller.
It maintains its own database of suspicious numbers alongside national databases. This and similar apps offer additional features, like call screening and the ability to block numbers without caller ID information.
Spoofed caller ID isn’t always bad
We’ve already talked about why caller ID isn’t perfect — spoofing being the most untrustworthy and invasive of them all. So, why does spoofing exist?
It’s actually used all the time (in totally legal ways) without most people ever noticing.
Law enforcement agencies may spoof numbers for undercover operations or handling matters of national security issues. A court order may allow spoofing to protect witnesses in a sensitive case. Anti-spam services may use spoofed numbers to trap and identify spam callers.
But what about normal businesses — can they legally spoof numbers?
If they don’t intend to harm anyone, businesses are allowed to modify or spoof their caller ID. Companies using VoIP systems might display toll-free numbers for outgoing calls, even if they were made from a different number.
Delivery apps often mask the numbers of the drivers and customers to protect their privacy, and an ecommerce company might use local numbers to boost call engagement.
Healthcare providers might use it to protect patient privacy by displaying a central office number rather than the direct line of a doctor or nurse.
When you think about it, having the ability to spoof numbers makes a lot of sense. Of course, there will always be people who abuse it.
When does spoofing become illegal?
There’s a lot of gray area, despite there being laws in place — notably the Truth in Caller ID Act of 2009, which prohibits people from spoofing numbers with the intent to defraud, harm, or obtain something of value.
But we all know that that doesn’t stop people from trying. Some of the most common illegal uses of call spoofing include:
- Telemarketing scams: Spoofing makes it easy to impersonate legitimate businesses or agencies, tricking victims into revealing personal information or sending money.
- Phishing attacks: By appearing as a trusted source, like a bank or credit card company, scammers lure victims into sharing information, clicking malicious links, or downloading malware.
- Extortion and harassment: Spoofers can anonymously threaten or intimidate.
- Identity theft: By posing as someone else, spoofers gain access to personal information or financial accounts.
You may be familiar with these scenarios: when a fraudster spoofs a call from a distressed “grandchild” who pleads for emergency financial assistance from their grandmother. Or when bad actors demand money to complete a shipment for a purchase that a person may or may not have even made.
These are just a few examples, and the tactics used by scammers are constantly evolving. Many now come via text and even local numbers in your area to trick you into answering.
The best advice? Be weary until you can confirm who you’re talking to.
If you’re ever unsure, hang up and Google the number. If it’s a business, call their public phone number and say you got disconnected — if the call was genuine, they’ll know what you’re talking about. If not, it was most likely someone spoofing their number.
SEE: Learn more ways to see if you’re getting a spam call.
Masking your own caller ID with *67
While you can’t control spoofing, you can safeguard your privacy when making a call.
All you have to do is dial *67 before the number you’re calling— your name and number will remain hidden. Instead, the recipient will likely see something like “Private,” “Blocked,” or “Unknown.”
However, this isn’t foolproof. Some networks don’t respect the blocking code, and many VoIP services or older systems might bypass it altogether.
If you ever receive a call from a private, blocked, or unknown number, you’re not out of luck if something happens. Law enforcement may still be able to trace the call using the caller’s IP address.
Ultimately, *67 offers a good first line of defense for occasional privacy needs.
But for better protection, using advanced call-blocking apps with call masking capabilities or upgrading to a VoIP service gives you more control over what others see when you call.