It happens to everyone. You’re trying to trade in your old device, or maybe you’re just buying a screen protector on Amazon and realize you have absolutely no idea if you’re holding an iPhone 13, a 14, or that new iPhone 16e everyone is talking about. They all kind of look like glass rectangles, right? Especially now that Apple has moved to the "Action Button" on almost everything and the camera bumps keep getting more massive.
Honestly, guessing is a bad idea. If you buy a Pro Max case for a standard Plus model, you're going to be disappointed. If you tell a trade-in site you have an iPhone 15 Pro but it’s actually the base 15, your quote is going to tank the second it hits the warehouse.
How do I know which iPhone I have without just guessing based on the color? It’s actually pretty easy if the phone turns on, but even if it’s a dead brick, there are ways to play detective.
The Settings Shortcut: Your Most Reliable Bet
If your screen works, stop squinting at the camera lenses. Just dive into the software. This is the only way to be 100% sure because it pulls the data directly from the logic board.
- Open the Settings app.
- Tap General.
- Hit About.
Right there at the top, you’ll see "Model Name." It’ll say something like iPhone 17 Pro or iPhone SE (3rd generation).
But wait. Sometimes you need the technical model number—that weird code starting with an "A." If you look at the line labeled Model Number, you might see a long string like MNHG3LL/A. That’s the part number (it tells you the region and storage). Tap that string once. It will flip over to reveal a much shorter code, like A3101.
That "A" number is the universal ID. If you're looking for specific repair parts or checking network compatibility for a trip abroad, that's the number that actually matters.
What if the Phone Won't Turn On?
This is where things get a bit more "Inspector Gadget." Apple hasn't printed the model name on the back of the phone since... well, basically forever. If the battery is dead and you don't have a charger, you have to look for physical clues.
The SIM Tray Trick
On almost every iPhone from the iPhone 4 up to the iPhone 13 (and international versions of newer ones), the model number is actually etched into the SIM tray slot. Pop that tray out with a paperclip. You might need a magnifying glass or a very bright light, but the "Axxxx" number is usually right there on the top side of the tray or inside the hinge.
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Note for US users: If you have an iPhone 14 or newer bought in the States, you don't have a SIM tray. Apple went all-in on eSIM. In that case, look at the USB-C port (or Lightning port if it's older). Sometimes the model info is laser-etched inside the connector port, though it's incredibly hard to read without a macro lens.
Physical Telltales
If you're still stuck, look at the charging port.
- USB-C: If it has a pill-shaped USB-C port, you have an iPhone 15, 16, or 17 series.
- Lightning: If it’s that small, solid 8-pin connector, it’s an iPhone 5 through iPhone 14.
- The "Action Button": Does it have a toggle switch for silent mode above the volume buttons? If it has a button instead of a switch, you're likely looking at an iPhone 15 Pro or any model from the iPhone 16 or 17 lineups.
Checking Your Apple ID From Another Device
You've probably forgotten that Apple keeps a neat little list of everything you own. If the mystery iPhone is signed into your iCloud account, you don't even need to touch the phone to identify it.
Grab another iPad, Mac, or even a friend's phone and log into appleid.apple.com. Once you're in, navigate to the Devices section. Every iPhone ever linked to your account will show up there with its official name, serial number, and even the OS version it was last running.
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This is incredibly helpful if the phone is shattered and the screen is just a mosaic of black ink and green lines.
Why the "A" Number Matters in 2026
You might wonder why we care about "A2849" vs "A3102." In 2026, the secondary market is huge. With the release of the iPhone 17 Air and the iPhone 16e, the physical differences between models are getting thinner—literally.
For instance, the iPhone 17 and the iPhone 17 Pro look remarkably similar at a glance, but the internal hardware for Apple Intelligence features varies. Knowing your exact model number ensures:
- You download the correct IPSW firmware if you're restoring via a Mac.
- You get the right battery replacement (the iPhone 16 Plus and 17 Plus batteries are NOT interchangeable).
- You know if your phone supports the latest 6GHz Wi-Fi bands or satellite SOS features.
Summary of Quick Identifiers
If you’re standing in a thrift store or looking at a drawer of old tech, use this mental checklist:
- Flat edges + 3 cameras: Pro model (12 or newer).
- Round edges + Home button: Likely an iPhone 6, 7, 8, or SE 2/3.
- USB-C + No "Pro" cameras: iPhone 15 or 16/17 base models.
- Glass back + No markings: Post-iPhone 8.
Once you find that "A" number—whether in Settings or on the SIM tray—just type it into Google. Apple’s official "Identify your iPhone model" support page is the gold standard for cross-referencing those numbers.
Now that you know exactly what you’re holding, you can finally buy that case or check your trade-in value with total confidence. If you're planning to sell it, make sure to check the "About" section one last time to verify the storage capacity too, as that's the biggest factor in what it's worth.