How to Check Your Phone Number When *#100# Doesn’t Work
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In many countries, dialing a USSD code like *#100# instantly displays your phone number. But this trick doesn’t always work?some carriers block it, some phones don’t support it, and on eSIMs it often fails entirely. If you’re stuck, don’t worry: there are many other reliable ways to confirm your own number. This article explains each method, step by step, so you’ll never be left guessing.
Why *#100# May Fail
USSD (Unstructured Supplementary Service Data) codes rely on the carrier’s network to respond. If the network doesn’t support the query, the request times out or shows an error. Other reasons include:
Your carrier has disabled the code for prepaid or eSIM users.
Roaming conditions block certain network requests.
Dual-SIM phones sometimes only process the command on one SIM slot.
Check Inside Your Phone Settings
Android: Go to Settings → About Phone → Status → SIM status. Look for “My phone number.”
iPhone: Open Settings → Phone. Your number is listed at the top as “My Number.”
Carrier and SIM Toolkit Options
Most SIM cards include a “SIM Toolkit” app that shows balance and profile information, often including your number. Some carriers also display it in their official mobile app once you log in.
Look for an app called “SIM Toolkit” or “Carrier Services.”
If you installed your carrier’s app (e.g., My Vodafone, My T-Mobile), check the account page.
Call or Text Another Phone
Borrow a friend’s phone.
Send them a message or call. Your number will appear on their screen.
Save it to your contacts for easy access later.
Use SMS-Based Number Check Tools
If you don’t have a second device, online services can reveal your number. For example, our CheckMyNumber homepage provides a tool: simply send an SMS to our test line, and your number appears instantly in your browser.
Works globally with most carriers.
No extra apps or codes required?just a regular SMS.
Ask Your Carrier Directly
Call customer support from your SIM. The automated system usually announces your number.
Some carriers provide number lookup codes other than *#100#, like *222# or *131#.
Tips to Avoid This Problem in the Future
Save your number in multiple places so you won’t be caught off guard again:
Store it under “My Number” in your contacts.
Write it down inside your SIM ejector case or phone box.
Add it to cloud notes (Google Keep, iCloud Notes).