Does My Cell Phone Know My Phone Number?

Yes, your cell phone typically knows your phone number. This information is stored in the phone's settings and is often automatically retrieved from your SIM card. You can usually find your phone number in the settings menu under Device Information.

Your Phone Number and SIM Card

Your phone number is assigned by your carrier and is associated with your SIM card. Along with other information, the SIM card contains its unique serial number (ICCID) and the international mobile subscriber identity (IMSI) number, which is what the carrier uses to tie your specific number to that specific SIM card.

So, your phone “knows” your phone number as it is able to retrieve the information from the carrier. This information is not stored in the SIM, but the phone uses a feature to retrieve it from the carrier. Most smartphones display this information in some setting screen under something like Device Information.

Without a SIM card, your phone does not have a number. This is why your phone number is not visible in the phone’s settings until a valid SIM card is inserted.

A Personal Experience

I used to list my own number under my name until I obtained a number that was so easy to remember. When I travel to Bali, I often write down the number on the back of the hotel business card, and during the trip, I stick the number on the back of the hotel business card. This is helpful for taxi drivers as my pronunciation of Indonesian words is poor.

Phone Number on a Smartphone

If you are asking if your phone knows your phone number before you enter your SIM card, the answer is no, unless you provide it. If you are asking if it discovers your mobile number after you insert the SIM card, the answer is yes. In my smartphone, I can find my phone number in the settings menu. I could show you if I had a photo editor on my phone to block out my cell number.

The Only Way for Your Phone to Know Your Number

The only way your cell phone can know your phone number is if you insert a SIM card. Your phone number and, sometimes, your contacts are stored on the SIM card's memory. This is the only way your phone will know your number.