Where to find your serial number depends on your laptop's operating system

Your laptop's serial number is a unique identifier printed or etched on the device itself, and also stored in your system files. The fastest way to find it is to look at the bottom or back of your laptop — most manufacturers print it there along with other hardware information. If the label has worn away or you need to verify it digitally, you can pull it from your operating system in under a minute.

The physical location varies slightly by brand. On Dell, HP, and Lenovo laptops, the serial number is usually on a white or silver sticker on the bottom panel. On Apple MacBooks, it's printed on the bottom case or inside the battery compartment (on older models). Asus and other manufacturers typically place it on the bottom as well. The label usually shows the model number, serial number, and sometimes a barcode.

If you can't access the physical label — because the laptop is sealed, the sticker is damaged, or you're troubleshooting a device you can't open — your operating system stores this information and you can retrieve it without opening anything.

Key Takeaways

  • The serial number is printed on a sticker on the bottom or back of most laptops, alongside the model number and barcode.
  • On Windows, you can find it by opening Command Prompt and typing wmic bios get serialnumber, then pressing Enter.
  • On Mac, go to Apple menu > About This Mac > System Report, then look for Serial Number in the Hardware section.
  • You need the serial number for warranty claims, device registration, theft recovery, and technical support from the manufacturer.
  • Write down or photograph your serial number and store it somewhere safe — it's the only way to prove ownership if your laptop is lost or stolen.

Finding the serial number on Windows laptops

The quickest digital method on Windows is to use Command Prompt. Click the Start button, type cmd, and open Command Prompt (the black window). Type wmic bios get serialnumber exactly as written, then press Enter. Your serial number will appear on the next line.

If Command Prompt doesn't work or you prefer a graphical method, you can also check System Information. Press the Windows key and R together, type msinfo32, and press Enter. In the window that opens, look for "System Serial Number" in the list on the right side. This shows the same information as the Command Prompt method.

A third option is to check Device Manager. Right-click the Start button, select Device Manager, then expand "Processors" or any hardware category. Right-click on an item, select Properties, and go to the Details tab. From the dropdown menu, select "Hardware IDs" — the serial number may appear in the value field, though this method is less reliable than the other two.

Finding the serial number on Mac laptops

On a Mac, the serial number is easiest to find through System Report. Click the Apple menu in the top-left corner, select "About This Mac", then click "System Report". In the window that opens, you'll see "Serial Number" listed in the Hardware section near the top. Copy or write down the alphanumeric code next to it.

If you're running an older version of macOS, the path may be slightly different — click Apple menu > About This Mac > More Info instead of System Report. The serial number will still be visible in the Hardware section.

You can also find the serial number printed on the bottom case of your MacBook, or on the battery itself if you remove it. On newer MacBooks with non-removable batteries, the number is only on the case or in System Report.

Why manufacturers and support teams ask for the serial number

The serial number is how a manufacturer links your specific device to its warranty, repair history, and technical specifications. When you contact Apple, Dell, or HP support, they use it to pull up exactly what components are in your laptop, what warranty coverage you have, and whether any recalls apply to your model. Without it, they're working from a generic product template rather than your actual device.

It's also the proof of ownership that matters most if your laptop is stolen or lost. Police reports and insurance claims both require the serial number. If your device is recovered or someone tries to sell it, the serial number is how it gets traced back to you. Registering your serial number with the manufacturer or with a device tracking service creates an official record.

Registering your serial number for warranty and theft protection

Most manufacturers let you register your device on their website using the serial number. For Dell, go to dell.com and sign into your account, then add the device. For HP, visit hp.com/support and register under My Devices. Apple automatically links your serial number to your Apple ID when you set up a new Mac, but you can also view it in System Preferences > General.

Registration doesn't change your warranty coverage — that's determined by the purchase date and your proof of purchase — but it does create a record that you own the device. If you lose the laptop and someone else tries to register it, the manufacturer knows it's already claimed.

Beyond manufacturer registration, consider writing down your serial number and storing it somewhere separate from your laptop — a notebook at home, a photo in your email, or a note in a password manager. If your laptop is stolen, you'll need this information immediately, and you won't have access to the device itself to look it up.

What to do if the serial number label is damaged or missing

If the sticker on the bottom of your laptop is worn, faded, or missing entirely, the digital method is your only option. Use the Command Prompt method on Windows or System Report on Mac to retrieve it from the system files. This number is just as valid as the one on the label — it's the same identifier stored in your device's firmware.

If you're buying a used laptop and the seller can't provide the serial number or it doesn't match what's in the system, that's a red flag. A legitimate seller should be able to show you the number on the device and verify it digitally. Mismatched or missing serial numbers can indicate a stolen or refurbished device that's been altered.

Serial number versus model number and service tag

The label on your laptop usually shows three pieces of information: the model number, the serial number, and sometimes a service tag or asset tag. The model number tells you the product line — for example, "HP Pavilion 15" or "Dell XPS 13". The serial number is unique to your individual device. The service tag (used by Dell) or asset tag (used by some business laptops) is another identifier, sometimes shorter than the full serial number.

When contacting support, they usually ask for the serial number first, but having the model number handy is also useful. If you're looking at a label and see multiple codes, the serial number is typically the longest alphanumeric string, often 8 to 15 characters.

Frequently Asked Questions

Can I find the serial number if my laptop won't turn on?

Yes. If the device won't power on, the physical label on the bottom or back is your only option. You don't need the laptop to be running to read a printed sticker. If the label is damaged or missing and the device won't start, you may not be able to retrieve the serial number without opening the device or contacting the manufacturer with proof of purchase.

Is the serial number the same as the product key or license key?

No. The serial number identifies the physical hardware device. The product key or license key (usually found on a sticker or in your email receipt) is for software like Windows or Microsoft Office. They're completely separate. You need the serial number for hardware support and warranty claims, and the product key for software activation and support.

What if two laptops show the same serial number?

This shouldn't happen — each device should have a unique serial number. If you see the same number on two different laptops, one of them is likely counterfeit, refurbished with an altered number, or there's an error in how you're reading the label. Contact the manufacturer with both devices and proof of purchase to investigate.

Do I need the serial number to sell my used laptop?

You should provide it to the buyer so they can register the device with the manufacturer and verify it hasn't been reported stolen. It's also good practice to remove your accounts and reset the device before handing it over. The buyer will want to confirm the serial number matches what's in the system to ensure they're getting a legitimate device.