Since most people rarely need to text or call their own mobile number, remembering it isn’t a priority, especially for those on postpaid plans who don’t need to provide contact details for service renewal. However, knowing your mobile number is as essential as knowing your own name. There may be situations where you suddenly need to share your contact information without a business card. If you don’t know or have forgotten your number, you can retrieve it directly from your SIM card (Subscriber Identity Module).
Contact Your Service Provider

Take the SIM card to the store where you purchased it. If you find an old SIM card but don’t have a phone to check it, bring the card to a store operated by the same carrier. The staff will be able to identify the phone number for you.

Contact your service provider. If you have a working phone but prefer not to use it to activate the SIM card, call the customer service hotline of your carrier. Almost all SIM cards have a serial number printed on them. Read this number aloud to the customer service representative and ask for the phone number associated with that SIM.

Understand new SIM cards. Many carriers do not assign a phone number until the SIM is activated. When you purchase a brand-new SIM card, it may not yet have a phone number. The number is assigned only after you insert the SIM into a phone and activate it.
Use the SIM card on any phone

Use your network's code. A few carriers provide a special code that you can dial or text to retrieve your phone number:
- Vinaphone customers can dial *110# and press the call or OK button.
- Viettel customers can send a text with the syntax TTTB to 1414.
- Mobifone customers can dial *555# and press the call or OK button.
- Other carriers may or may not support this feature. You can search online using the keywords "check phone number" along with your carrier's name.

Call customer service. Some SIM cards do not display the phone number in the settings, no matter which phone you insert them into. In this case, you can call the customer service of the SIM provider.
- If you are calling from the phone with the SIM card in question, the carrier may be able to retrieve the number immediately. Otherwise, have the SIM card ready to read the serial number aloud to them.

Send a text or call another number. Use the SIM card whose number you want to know. Any phone that displays caller information will show the phone number of the SIM card you are using to make the call, unless you are using a private number.
iPhone
Use the Phone Settings app

Open "Settings." Tap on the app icon with a gear shape located on the Home screen to access the device settings.

Tap on "Phone." Select “Phone” from the list of options in the Settings menu.

Check the "My Number" section. This section displays the phone number of the SIM card currently inserted in your phone.
On the Contacts List

Open your contact list. Tap the green phone icon located in the app dock at the bottom of the screen or anywhere on the Home screen to access your contacts.

Swipe down to the top of the contact list. Scroll to the beginning of the list, place your finger above the first contact, and swipe down. The contact details, including the current SIM card's phone number, will appear.
Connect with iTunes

Launch iTunes on your computer. This method works seamlessly on both Macbook and Windows PCs.
- Warning: If you've never connected your iPhone to a computer before, proceed with caution. A single error during the process could result in the loss of music on your device.

Connect your iPhone to the computer. Every iPhone comes with a USB cable. Plug one end into the charging port of your phone and the other end into a USB port on your computer.
- This method is equally effective for wireless synchronization.

Log in to the iTunes Store if prompted. Some users may encounter a pop-up message saying "Sign in to the iTunes Store." If this appears, enter the
Apple ID associated with your phone.
- Skip this step if no such notification appears.

Click "Cancel" if asked about synchronization. Some users may see a prompt asking if they want to erase and sync their device. If this happens, select "Cancel." Syncing on someone else's computer could delete all the music on your iPhone.
- Ignore this step if the prompt doesn't show up.

Click the device button in iTunes. The location of this button depends on your iTunes version:
- On iTunes 12: Click the small phone icon near the top-left corner.
- On iTunes 11: Click the "iPhone" button near the top-right corner. If it's not visible, click "Library" at the top-right to exit the store. If you still can't find it, select "View" from the dropdown menu and then click "Hide Sidebar."
- For iTunes 10 and earlier: Locate the "Devices" section in the left-hand sidebar. Click the name of your device listed under this section.

Locate your phone number. Your mobile number will appear at the top of the iTunes window, near the iPhone icon.
- If you can't find your phone number, click on the "Summary" button. This option might be located in the sidebar on the left or as a tab at the top of the screen.
Android Device

Access the Settings app. Tap on the gear icon among the apps on your screen to open the device's settings menu.

Tap on About Device or About Phone. Select "About Device" or "About Phone" from the list of options that appear in the Settings menu. You may need to scroll down to find it.
- On the LG G4, you need to tap on the "General" tab first, then select "About Phone".

Tap on Status or Phone Identity. Depending on your device, one of these options will lead you to your phone number.

Check your phone number. Scroll down on the Status screen to locate the “My phone number” section, where you can view the SIM card's number in your phone.
- If your number isn’t visible, look for the "SIM Status" option. Tap on it and find your phone number in the final submenu.
Windows Phone

Access your contact list. Tap on the “Phone” icon from the home screen of your Windows phone to open the address book.

Explore additional options. Click on the three-dot icon located at the bottom-right corner of the screen to discover extra features.

Navigate to Settings. Select the “Settings” app from the displayed options to configure your contact list preferences.

Check your number. Swipe vertically on the screen to locate your SIM card's phone number under the “My phone number” section.

Navigate alternative menu layouts. Certain Windows mobile devices feature slightly different menu structures:
- For the LG Optimus Quantum: Menu → Settings → Applications → Phone → Check "My Phone Number"
Blackberry Phone

Discover more apps. Swipe left on the screen to reveal additional applications available on your Blackberry device.

Access the Settings app. Tap the gear icon from the app screen to open the System Settings menu.

Navigate to the Category section under “About.” Select “About” from the System Settings screen and tap on “Category” to open a dropdown list.

View your phone number. Tap on “SIM Card” from the dropdown list, and your SIM card's mobile number will be displayed on the screen.
iPad

Tap on "Settings" with the grey gear icon.

Tap on "About," an option usually located near the top of the list.

Locate your SIM card number. This information might be labeled as "Cellular Data Number."
- iPads are not designed for making calls. They only use SIM cards for data connectivity.
Tips- The methods above apply only to standard GSM (Global System for Mobile Communications) phones or devices that use SIM cards for operation.
- If you have a CDMA (Code Division Multiple Access) phone or a device without a SIM card, contact your service provider to learn how to retrieve your phone number.
Warning- Some carriers may automatically deactivate services if a SIM card remains unused for a certain period. If you cannot activate an old SIM card, it might no longer be functional.