Your laptop's serial number is usually a combination of letters and numbers printed on a sticker underneath the device or inside the battery compartment

The fastest way to find it is to flip your laptop over and look for a barcode label on the bottom or back panel. Most manufacturers print the serial number there alongside the model number and regulatory information. If you can't find a sticker, check inside the battery compartment — some older laptops have it there instead.

If the physical label is worn away or missing, you can retrieve the serial number from your operating system using built-in tools. The method differs depending on whether you use Windows, macOS, or Linux, but each takes less than a minute.

Key Takeaways

  • The serial number is almost always on a sticker on the bottom of your laptop or inside the battery compartment.
  • Windows users can find it by opening Command Prompt and typing wmic bios get serialnumber, then pressing Enter.
  • Mac users can click the Apple menu, select About This Mac, and look for the serial number in the System Report window.
  • Linux users can open a terminal and type sudo dmidecode -s system-serial-number to retrieve it from the system firmware.
  • You need the serial number for warranty claims, repairs, theft recovery, and tracking devices on a network.

Finding the serial number on the physical device

Start by shutting down your laptop completely and unplugging it from power. Turn it over so the bottom is facing up. Look for a rectangular sticker or label that contains small text, a barcode, and regulatory symbols like FCC or CE marks. The serial number is usually printed on this label in a line that says "S/N", "Serial No.", or "SN".

The label is typically white or silver and located near the center or one corner of the bottom panel. On some models — particularly older ThinkPads, MacBook Pros, and Dell Latitudes — the serial number appears multiple times on the same label. Write down the number exactly as it appears, including any letters or dashes.

If the bottom label is missing or illegible, remove the battery if your model allows it. Some laptops have a second label inside the battery compartment. If your laptop has a non-removable battery, move to the operating system method instead.

Retrieving the serial number in Windows

Open the Start menu and type cmd to find Command Prompt. Right-click it and select "Run as administrator" — this step is required for the command to work. A black window will open.

Type the following command exactly as shown: wmic bios get serialnumber. Press Enter. The serial number will appear on the next line. Copy it carefully, as it may contain characters that look similar (like the letter O and the number 0).

If the command returns "No Instance(s) Available", your laptop's firmware may not expose the serial number through this method. In that case, the physical label is your only option. If you see a long string of characters that doesn't match what's on the physical label, the physical label is the authoritative version — manufacturers sometimes use different serial numbers for different purposes.

Retrieving the serial number on macOS

Click the Apple menu in the top-left corner of your screen and select About This Mac. A window will open showing basic information about your computer.

Click the System Report button at the bottom of the window. A new window titled "System Report" will open. Look for the line labeled Serial Number in the main section at the top. The serial number appears next to it. You can highlight and copy it directly from this window.

If you're running an older version of macOS, the serial number may appear in the main About This Mac window without needing to open System Report. Either way, the number you see here matches what's printed on the physical label underneath your MacBook.

Retrieving the serial number in Linux

Open a terminal window. You can usually do this by right-clicking on the desktop and selecting "Open Terminal" or by searching for "Terminal" in your applications menu.

Type the following command: sudo dmidecode -s system-serial-number. Press Enter. You may be prompted to enter your password — this is normal, as the command requires administrator access. The serial number will appear on the next line.

If the command returns nothing or an error, your system firmware may not store the serial number in a location that dmidecode can read. This is common on some custom-built Linux machines or older hardware. In that case, check the physical label on your device instead.

Why you need the serial number and what to do with it

The serial number is the unique identifier for your specific laptop. You need it for warranty claims — manufacturers use it to verify coverage dates and what repairs are included. If your device is stolen, you can provide the serial number to law enforcement and your insurance company to help track it down.

IT departments use serial numbers to track devices on corporate networks and manage software licenses. If you're selling your laptop, the buyer may ask for it to verify the device's history and authenticity. Some repair shops require it before they'll service your machine, particularly for out-of-warranty work.

Store the serial number somewhere safe — take a photo of the label or write it down and keep it with your device documentation. If you ever need to contact the manufacturer for support, having the number ready will speed up the process.

What to do if you can't find the serial number

If the physical label is completely missing and the operating system commands return nothing, contact the manufacturer's support line. Have your laptop's model number ready — this is usually printed on the same label as the serial number, or you can find it in the About This Mac or System Information window. The manufacturer can sometimes look up the serial number based on the model and purchase date.

If you purchased the laptop from a retailer, check your receipt or order confirmation — some retailers print the serial number on the documentation. Your email confirmation from the purchase may also contain this information.

For used laptops where the original owner is unavailable, the serial number may be unrecoverable. This doesn't prevent you from using the device, but it does mean you won't be able to claim warranty service or prove ownership if the device is lost.

Frequently Asked Questions

Is the serial number the same as the model number?

No. The model number identifies the type of laptop (like "ThinkPad X1 Carbon" or "MacBook Pro 16-inch"). The serial number is unique to your individual device — no two laptops have the same serial number, even if they're the same model. Both appear on the same label, but they're different numbers.

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

Yes. The physical label on the bottom or inside the battery compartment doesn't require power to read. If your laptop won't start, the sticker method is your only option. You don't need the operating system to access the serial number.

What if the serial number on the sticker doesn't match what Windows or macOS shows?

Use the number on the physical sticker. Manufacturers sometimes use different serial number systems for different purposes — the one printed on the label is the official identifier for warranty and ownership. If you're contacting support, always provide the number from the sticker.

Do I need the serial number to sell my laptop?

Not always, but it's helpful. Buyers may ask for it to verify the device's history and check if it's been reported stolen. Having the serial number available shows you know the device's details and can help build trust in the transaction.

Can someone use my serial number to claim my laptop is theirs?

Unlikely. The serial number alone doesn't prove ownership — you'd also need the original receipt, proof of purchase, or account information tied to the device. However, don't share your serial number publicly or with people you don't trust, just as you wouldn't share your device's location or access credentials.