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

Your computer's serial number is a unique identifier printed or etched on your machine and also stored in your system files. On Windows, the fastest way is to open Command Prompt, type wmic bios get serialnumber, and press Enter—your serial number appears in seconds. On a Mac, click the Apple menu, select About This Mac, then look for Serial Number in the window that opens. On Linux, open a terminal and type sudo dmidecode -s system-serial-number to retrieve it from your system firmware.

If you prefer not to use the command line, Windows also lets you find the serial number through Settings. Go to Settings > System > About, scroll down, and look for Device specifications—the serial number appears under System serial number. This method works on Windows 10 and 11. Mac users can also find it printed on the bottom or back of their machine, though the on-screen method is more reliable for laptops.

Key Takeaways

  • On Windows, type wmic bios get serialnumber in Command Prompt to see your serial number when ready.
  • On Mac, open About This Mac from the Apple menu to find the serial number listed in the system information window.
  • Your serial number is also printed physically on your computer—usually on the bottom of a laptop or the back of a desktop tower.
  • You may need your serial number for warranty claims, technical support, or to prove ownership if your computer is lost or stolen.

Using Command Prompt on Windows

Command Prompt is the quickest route on any Windows machine. Press the Windows key, type cmd, and open Command Prompt (you do not need administrator rights for this task). At the prompt, type wmic bios get serialnumber exactly as written, then press Enter. Your serial number appears on the next line.

If that command does not work, try wmic csproduct get identifyingnumber instead—some manufacturers store the serial number in a different location. Both commands pull the information directly from your computer's firmware, so the number you see is the official one your manufacturer recognizes.

Finding it through Windows Settings

If you prefer a graphical interface, Windows Settings shows your serial number without opening Command Prompt. Click the Start button, type settings, and open the Settings app. Navigate to System on the left sidebar, then scroll down and click About.

In the Device specifications section, look for System serial number. The number displayed there matches what you would see in Command Prompt. This method works identically on Windows 10 and Windows 11, though the layout may differ slightly between versions.

Locating the serial number on Mac

On any Mac, click the Apple menu in the top-left corner and select About This Mac. A window opens showing your system information. Look for Serial Number in the main section—it appears as a string of letters and numbers. This is your computer's unique identifier recognized by Apple and authorized repair shops.

You can also find the serial number printed on the physical machine. On MacBook models, it is usually on the bottom of the chassis. On iMac or Mac mini, check the back or bottom. However, the on-screen method is more reliable because it shows the exact number your system recognizes, which matters if you ever need to reference it for support or warranty purposes.

Retrieving the serial number on Linux

Linux systems store the serial number in the system firmware, accessible through the dmidecode tool. Open a terminal and type sudo dmidecode -s system-serial-number, then enter your password when prompted. Your serial number appears on the next line.

If dmidecode is not installed on your system, you can install it through your package manager. On Ubuntu or Debian-based systems, type sudo apt install dmidecode. On Fedora or Red Hat systems, type sudo dnf install dmidecode. After installation, run the dmidecode command again to retrieve your serial number.

Why you might need your serial number

Your serial number proves ownership and identifies your specific machine to manufacturers and repair shops. If you need to claim a warranty, the manufacturer uses your serial number to verify the purchase date and coverage terms. If your computer is stolen or lost, providing the serial number to police or your insurance company helps prove it belongs to you.

Technical support teams also ask for your serial number when you contact them, because it tells them exactly which model and manufacturing batch your computer came from—information that helps them diagnose problems faster. Some software licenses are tied to your serial number as well, so you may need it when reinstalling programs or transferring licenses to a new machine.

Finding the serial number on the physical machine

Every computer has its serial number printed or engraved somewhere on the chassis. On laptops, check the bottom panel first—you may need to remove the battery or open a service door to see it. On desktop towers, look on the back panel near the power connector or on the side panel. On all-in-one computers like iMac, check the back or bottom edge.

The serial number is usually printed on a label or engraved directly into the plastic or metal. It appears alongside other information like the model number, manufacturing date, and regulatory certifications. If the label is worn or missing, the on-screen method (Command Prompt, About This Mac, or dmidecode) is your reliable backup, since the system firmware always contains the correct number.

Frequently Asked Questions

Is the serial number the same as the model number?

No. Your model number identifies the type of computer (like "MacBook Pro 16-inch" or "Dell XPS 13"), while your serial number is unique to your individual machine. Both are useful, but they serve different purposes. The model number tells support what kind of hardware you have; the serial number tells them which specific unit.

Can I find the serial number if Windows won't start?

Yes. If your computer will not boot, the serial number is printed on the physical machine. Check the bottom of a laptop or the back of a desktop. You can also boot into the BIOS or UEFI firmware (usually by pressing F2, F10, or Delete during startup) and look for the serial number there, though the physical label is faster if you can access it.

What if the command prompt shows a different number than the physical label?

The number from Command Prompt is the one your system recognizes and the one manufacturers use for support and warranty. If the physical label differs, the label may be worn, misread, or from a refurbished unit. Always use the number from Command Prompt or About This Mac when contacting support or filing a claim.

Do I need the serial number to sell my computer?

You do not need it to sell, but providing the serial number to the buyer helps them verify the machine's history and authenticity. Some buyers ask for it to check if the computer is reported stolen or blacklisted. Having it available shows transparency and can increase buyer confidence.

Can someone use my serial number to access my computer remotely?

No. The serial number is a hardware identifier, not a password or access code. It cannot be used to log in, unlock your computer, or gain remote access. It is safe to share your serial number with manufacturers, repair shops, or support teams when you need help.