The moment CheckMyCaller.com earns its place is just before you act: before you return a missed call, confirm a detail or agree to a payment. A quick search of the number lets you see whether other people in the US or Canada have described the same opening line, the same company name or the same request, which is far more useful than deciding on instinct while someone is waiting on the line.
Pressure is the common thread in the calls people report. A caller may claim to be from your bank's fraud team, a government agency, a utility or a software company, and the story almost always comes with a deadline: an account about to be frozen, a charge to reverse, a device supposedly infected. The number on your screen adds nothing reliable to that story, because a familiar local area code can be displayed by someone calling from anywhere. If the call involves someone wanting remote access to your computer or payment for a fault you had not noticed, CheckMyCaller.com's guide to tech support scam calls sets out how that approach is run.
Keep a few fixed habits. Do not read out card numbers, bank details, passwords or one time verification codes to anyone who called you, no matter how much they already appear to know. Do not move money because a caller told you to. If there is any doubt, hang up, then reach the organization yourself using a number from your card, your statement or its official website rather than one the caller supplied.
Learn the patterns, not just the numbers. CheckMyCaller.com groups reports by common scam types, which is worth reading when the same tactic reaches you from a fresh number. Recognizing the script is the part that keeps working after a number stops calling.