HLR Lookup vs Other Phone Number Validation Methods: What’s the Most Reliable Way to Check if a Number Is Active?

Phone number validation is a critical step in ensuring that your contact lists comprise real, contactable people. Whether you're sending marketing SMS, verifying signups, or filtering leads, using the right method to check if a number is valid, active, and reachable can save money, reduce bounce rates, and improve overall data quality.

There are several methods available to validate phone numbers, but not all of them are equally effective. In this post, we compare the most common validation techniques including Regex, Carrier Lookup, and OTP verification against HLR Lookup, a powerful method that checks a number's real time status directly with the mobile network.

Overview of Phone Number Validation Methods

Method	Description	Best For
Regex / Format Validation	Checks if a number follows the correct syntax	Front-end input validation
Carrier Lookup	Identifies carrier and line type (mobile, landline, VoIP)	Filtering or targeting
HLR Lookup	Queries the live status from the mobile carrier's Home Location Register	Verifying if numbers are active, reachable and much more. Learn more by reading our What is a HLR Lookup? Blog post.
OTP Verification	Sends a one-time passcode to confirm user ownership	Securing user access, sign ups

HLR Lookup vs Regex Validation

Regex validation is often used on websites and apps to check that a phone number has the right format (e.g., correct country code and digit count). While this helps filter obvious errors, it doesn’t confirm whether the number actually exists or is active.

HLR Lookup, on the other hand, connects to the mobile network and confirms if the number is active, unreachable, or invalid. It also reveals if the number has been ported to another carrier.

Test HLR Lookup for free with 200 free credits

HLR Lookup vs Carrier Lookup

Carrier Lookup tools return metadata about the phone number including the current carrier, line type, and country. This is useful for routing messages or identifying VoIP numbers.

However, Carrier Lookup doesn’t tell you if the number is still in service. A number might belong to a carrier but still be inactive. HLR Lookup goes a step further by confirming if the number is reachable and live.

HLR Lookup vs OTP Verification

OTP (One-Time Password) verification is the gold standard for confirming that a user controls a phone number. It’s secure, but not scalable for batch validation and incurs SMS costs even when numbers are inactive.

HLR Lookup is ideal for pre-verification before sending OTPs helping you avoid sending codes to dead or unreachable numbers.

When to Use Each Method

• Use Regex and Carrier Lookup to catch format errors and sort number types.

• Use HLR Lookup to confirm if a number is actually active before launching SMS campaigns or lead outreach.

• Use OTP for secure logins or user verification.

Conclusion: HLR Lookup Is the Most Reliable, Scalable Option

When it comes to verifying if a phone number is active, reachable, and real, HLR Lookup offers the most comprehensive, scalable, and cost-effective solution.

Ready to Check a Number?

Don't waste time calling or guessing. Use our HLR lookup tool to instantly check if a number is real, active, and reachable

Check a number now