Every iPhone has a unique serial number, which can be used to identify the specific handset you own. You may need to know the serial number of your iPhone if you're unlocking it through your carrier, having it serviced, or selling it.

It's easy to locate, but figuring out exactly how to find the serial number on your iPhone depends on which model you own and whether you are able to turn on the phone.

How to find the serial number on any iPhone

If you have an iPhone 5 or later, here's how to find the serial number:

1. Open the Settings app.

2. Tap "General" and then tap "About."

3. On the About page, you should see the serial number. If you want to copy it, tap and hold the serial number and then tap "Copy" when the option appears.

If you have an iPhone 3G, iPhone 3GS, iPhone 4, or iPhone 4S, the serial number is on the SIM tray. See our article on removing your iPhone's SIM card to learn how open the SIM card tray.

How to find the serial number for any iPhone, even if you've lost the phone or it won't turn on

If you still own an even older iPhone, you'll find the serial number engraved on the back of the phone.

How to find an iPhone's serial number if you don't have your phone or it won't turn on

The easiest way to find your phone's serial number is by looking on the phone itself, but if that's not an option, there are still a few ways to find it.

If you have your original packaging, the serial number is printed on the barcode sticker on the box.

If you don't have the box, you can find it by going to your Apple ID page in a web browser.

1. In a browser, log into appleid.apple.com.

2. On your Apple ID page, scroll down to Devices and find the iPhone you need the serial number for.

3. Click the icon for the device. The serial number will appear in the pop-up window. You can copy and paste this number into an email or text message.

How to find an iPhone's serial number on another Apple device

If you have another Apple device — like a Mac or iPad, for example — that's linked to the same Apple ID, you can find your iPhone's serial number using that device as well.

1. On the other device, start the Settings app.

2. Tap your name at the top of the screen.

3. Scroll down to the list of other devices connected to your Apple ID.

4. Tap the entry for the iPhone. You'll see information about that phone, including the serial number.

Apple iPhone 11$499.00 from AppleDave JohnsonFreelance WriterDave Johnson is a technology journalist who writes about consumer tech and how the industry is transforming the speculative world of science fiction into modern-day real life. Dave grew up in New Jersey before entering the Air Force to operate satellites, teach space operations, and do space launch planning. He then spent eight years as a content lead on the Windows team at Microsoft. As a photographer, Dave has photographed wolves in their natural environment; he's also a scuba instructor and co-host of several podcasts. Dave is the author of more than two dozen books and has contributed to many sites and publications including CNET, Forbes, PC World, How To Geek, and Insider. Read moreRead less