Guides & references
Practical, plain-language articles on US and Canadian phone numbers, verification, and telecom fundamentals.
01
What is a VoIP number, and how do you spot one?
Understand the differences between VoIP, landline, and mobile numbers in the US and Canada — and why the distinction matters.
02
US & Canadian area codes, in one list
A complete NANP area code reference — every state, every province, plus overlay and toll-free codes.
03
How phone number validation actually works
What "valid" really means — format checks, HLR lookups, and the layers most people don't know about.
04
How to identify an unknown caller
Steps you can take before calling back a number you don't recognize.
05
E.164: the international phone format explained
Why every US and Canadian number should look like +1 followed by 10 digits — and what breaks when it doesn't.
06
How to protect yourself from spam calls
Practical steps that reduce robocalls and scam texts on iPhone, Android, and landline in the US and Canada.