How Does Caller ID Work and Its Effectiveness

When using caller ID, there are times when the information presented can seem vague or perhaps even absent altogether. For this reason we should all keep our wits about us when using caller ID and reading what it displays. In order to keep things simple, let’s break caller ID down into two categories, landlines and mobile phones.
Landlines
Caller ID is at its most effective when one landline is calling another landline. This is largely because there’s usually little distance between one fixed line and another, and the calls are usually local. Also, it’s far more likely for people to have their landlines listed in directories (mobile phones are ex-directory by default). The thing is, if a number is listed, you’re likely to get their name as well as their number on the caller ID screen. If a phone number is not listed, you may still see the phone number flash up, but there’ll be no other information. They key thing to note here is that with an ex-directory phone number, sometimes a number will come up, and sometimes it won’t. So in that sense the service can be pretty unreliable.
If calls are not local (very common in the US), then caller ID works in a slightly different way. If a number is not listed in the directory then the incoming call might instead tell you which area or state the call is coming from. This can be very useful for people in identifying unexpected calls or “cold calling”.
Mobile Phones
Caller ID on mobile phones are a slightly trickier issue, mainly because the system is easy to hack and ‘spoof’. Caller ID spoofing is becoming an increasingly large problem. It basically involves someone calling you but interfering with the Caller ID system so that a completely different and unassociated number pops up in place of theirs. This could allow someone who you’d previously blocked or decided to ignore still get in contact with you.
Caller ID on mobile phones is also a lot less likely to offer up any information about the person other than their number and where they’re calling from, so it can be difficult to find out who they are which can be unnerving if you’re not expecting a call. Thankfully, there are a lot of online services out there to help you search for people based on their phone numbers, and online telephone directories are an excellent place to start your search.

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