Where to find your serial number on Windows, Mac, and Linux

Your computer's serial number is a unique identifier printed or stored by the manufacturer. On Windows, you can find it by opening Command Prompt, typing wmic bios get serialnumber, and pressing Enter. The serial number appears on the next line. On Mac, click the Apple menu, select About This Mac, and look for the serial number in the System Report window. On Linux, open a terminal and type sudo dmidecode -s system-serial-number to display it.

If your computer is older or the command does not work, you can also find the serial number physically printed on a sticker. On laptops, check the bottom panel or the inside of the battery compartment. On desktop computers, look on the back panel or inside the case near the power supply. The serial number is usually a mix of letters and numbers, often 8 to 20 characters long, and may be labeled as "Serial Number," "SN," or "Service Tag."

Key Takeaways

  • Windows computers show the serial number through the Command Prompt command wmic bios get serialnumber.
  • Mac users can find the serial number in System Report under the Apple menu without needing any commands.
  • Linux systems require the terminal command sudo dmidecode -s system-serial-number to display the serial number.
  • Physical stickers on the bottom of laptops or inside desktop cases provide a backup way to locate the serial number if software methods fail.

Why you need your serial number

The serial number is required when you contact the manufacturer for warranty service, repairs, or technical support. It proves you own the device and helps the manufacturer pull up your specific model's history, any recalls, and what components are inside. Without it, support staff cannot verify your purchase or determine what parts your computer contains.

You also need the serial number to register your device for warranty coverage, to file an insurance claim if the computer is stolen or damaged, and to sell or donate the computer later. Some software licenses are tied to the serial number as well, so you may need it when reinstalling programs or transferring licenses to a new machine.

Getting the serial number from Windows using System Information

If Command Prompt feels unfamiliar, you can use the System Information tool instead. Press the Windows key and R together, type msinfo32, and press Enter. The System Information window opens. Look for "System Serial Number" in the list on the right side of the window. The serial number appears next to it.

This method works on all Windows versions from Windows 7 onward. If System Serial Number does not appear in the list, scroll down to see if it is listed under a different name like "Serial Number" or "Service Tag." Some manufacturers use different labels, so checking both methods (Command Prompt and System Information) gives you the best chance of finding it.

Getting the serial number from Mac using Terminal

Mac users who prefer the terminal can also retrieve the serial number without opening System Report. Open Terminal (found in Applications > Utilities), type system_profiler SPHardwareDataType | grep Serial, and press Enter. The serial number displays on the next line. This command works on all recent Mac operating systems.

You can also find the serial number by holding Option and clicking the System menu in the top-left corner, then selecting System Information. The serial number appears in the Hardware Overview section. Both methods take less than a minute and do not require administrator passwords.

Physical location of serial numbers on different computer types

Laptop serial numbers are almost always on a sticker on the bottom of the device. Flip the laptop over, look for a white or silver label, and scan it for the serial number. On some models, the serial number is printed directly on the plastic without a sticker. If the bottom does not have it, check inside the battery compartment or under the keyboard (though removing the keyboard may void your warranty).

Desktop computers usually have the serial number on a sticker on the back panel, often near the power connector or on the side of the case. Some manufacturers place it inside the case near the motherboard or power supply. If you open the case, take a photo of the sticker before closing it again so you have the number recorded. All-in-one computers like iMacs have the serial number on the back of the screen or on the stand.

What to do if you cannot find the serial number

If the physical sticker is missing or worn away, and the software commands do not return a result, contact the manufacturer's support team with your computer's model number instead. The model number is usually easier to find (often printed on the front or back of the device) and support staff can sometimes look up the serial number using your purchase receipt or the email address associated with your account.

If you bought the computer from a retailer, check your original receipt or the retailer's website account. Many retailers store the serial number in your order history. You can also check any warranty documentation or registration cards that came with the computer. If the computer is still under warranty, the manufacturer may have the serial number on file linked to your registration.

Keeping your serial number safe

Once you find your serial number, write it down or take a photo and store it somewhere you can find it later. Keep a copy in a document on your computer, in a password manager, or in a physical notebook. If your computer is stolen, you will need the serial number to report it to police and to your insurance company. Retailers and manufacturers also use it to check if a device is stolen before accepting returns or repairs.

Do not share your serial number publicly on social media or in online forums. While it is not as sensitive as a password, it can be used to impersonate you when contacting support or to claim ownership of a device you are selling. Treat it the same way you would treat a vehicle identification number on a car.

Frequently Asked Questions

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

No. The serial number identifies the physical device itself. A product key or license key is a separate code that unlocks software. Your computer has one serial number, but you may have multiple product keys for different programs installed on it.

Can I change my computer's serial number?

Changing the serial number stored in firmware is possible but voids your warranty and may violate laws in some places. The physical serial number on the sticker cannot be changed without damaging it. There is no practical reason to change it unless you are troubleshooting a specific technical issue, in which case contact the manufacturer first.

Do I need the serial number to sell my computer?

Yes. Buyers often ask for it to verify the device is genuine and not stolen. Having the serial number ready makes the sale faster and builds trust. You should also use it to deregister the computer from your account before handing it over.

What if the Command Prompt command returns nothing?

Some computers, especially older ones or those with custom operating systems, may not store the serial number in the BIOS. Try the System Information method instead, or check the physical sticker. If neither works, contact the manufacturer with your model number and purchase receipt.

Can I find the serial number remotely if I do not have access to the computer?

If you have remote access software installed, you can run the same commands from another device. Otherwise, you will need the physical device or the original purchase receipt. Contact the retailer or manufacturer with proof of purchase, and they can look it up for you.