Question: When I try to search the internet for a random phone number that called me, all the sites that say they offer free reverse lookups charge to get the information. Is there an actual free service that you know of?

Answer: Getting a phone call from a number you don’t recognize is very common, and not answering it is the right decision.

A legitimate friend or colleague will generally leave a voice message, so when they don’t leave a message, you can assume it wasn’t anything important.

If not knowing who called causes some level of anxiety, there’s not a simple, free way to absolutely determine who every caller was, but there are a few things you can try.

Identify when it's a scam caller

There are some clear red flags for calls that are scammers, starting with the area code. There are known international area codes that scammers use to lure victims.You can get a general idea of where any call is coming from by searching ‘XXX area code’ in Google, which may help you determine if it’s a call you’ve been anticipating or clearly an international scam.

Not only is it important not to answer the call, but it’s imperative that you never call or text back numbers with international area codes as they can be billable communications that aren’t covered by your phone’s calling plan. If you call the number, they’ll try to keep you on the call as long as possible to ring up expensive per-minute charges.

These types of scammers will often use the one-ring approach to entice victims to call them back.

Search your email inbox for clues on who called

If you think that the caller may have been someone you’ve interacted with before, it’s possible that you have their phone number in one of the email messages used in the past.

Try doing a search for the number in your email program just in case they happen to match. This is kind of a long shot as many larger businesses have a bank of phone numbers that can make outbound calls that can vary by a couple of digits, but it may shed some light.

Legitimate businesses may have phone number on social media

If the caller was a legitimate business, it’s possible that they list their phone number on various social media platforms, especially if you specifically search the Pages section on Facebook.

A simple Google search can uncover information

A more comprehensive search of legitimate business phone numbers can be done by simply searching on Google. If a legitimate business is using the number, their website/info will pop up in the results.

If you get a plethora of sites that claim they can provide the information for who owns the number, they’ll all likely be services that charge a small fee of a dollar or two.

Reverse lookup services might tell you what you already know

If you’ve attempted to get information from a site that claims that it’s free, you’ll likely end up at one of the larger services such as Spokeo or Intelius which charges a fee for ‘all the details’.

Both currently offer to provide whatever information they have in their databases for around $1 per number, but in my tests, they didn’t have anything more than what I was able to gather via various searches, so buyer beware.

Ken Colburn is founder and CEO of Data Doctors Computer Services, datadoctors.com. Ask any tech question at facebook.com/DataDoctors or on Twitter @TheDataDoc.

This article originally appeared on Arizona Republic: Getting calls from an unknown number? Find out who's on the other line