How to Use a SIM Card in a Windows 10 Laptop

To use a SIM card in a Windows 10 laptop, turn the laptop off and put the SIM in its SIM slot. Turn it on, then go to Start > Settings > Network & Internet > Cellular and select your mobile network. Turn on Let Windows keep me connected to connect by itself.

Applies to: Windows 10. Windows 10 reached end of support on October 14, 2025, and only PCs enrolled in Extended Security Updates still get security fixes, through October 12, 2027.

Before you start

• Your laptop needs a cellular modem. If there’s no Cellular page in Settings and no SIM slot, it can’t use a SIM. You can share your phone’s data instead with a hotspot.
• You need a data plan from a mobile operator that works with your laptop.
• Find the SIM slot. It’s often on the side or under a small cover. Check your laptop’s guide for the right SIM size.

Put the SIM card in

1. Turn off the laptop.
2. Push the SIM into the slot (use the tray tool if it has one) until it clicks.
3. Turn the laptop back on.

Connect to cellular data

1. Select Start > Settings > Network & Internet > Cellular.
2. Select your mobile network, then Connect if it doesn’t connect by itself.

3. Turn on Let Windows keep me connected to use cellular data whenever Wi-Fi isn’t there.

You can also select the network icon on the taskbar and select the Cellular tile.

Save your data

• Keep Data roaming options on Don’t roam unless your plan covers roaming.
• Windows treats cellular as a metered connection, so it uses less data in the background. You can apply the same limit to Wi-Fi by setting a metered connection in Windows 10.

Use an eSIM instead

Many newer laptops with cellular support also have an eSIM, so you don’t need a physical card. In Cellular > Advanced options, look for Manage eSIM profiles, select Add a new profile, and enter the activation code or scan the QR code your operator gives you.

Keep an eye on data use

Go to Settings > Network & Internet > Data usage, choose the cellular connection, and select Enter limit to set a monthly cap. Windows warns you as you get close.

Cellular settings worth knowing

These are on the Cellular page or under Advanced options. Names can vary slightly with your modem and operator.

• Use cellular instead of Wi-Fi: choose Never, When Wi-Fi is poor, or Always. “When Wi-Fi is poor” is handy in hotels and cafés with weak connections.
• Let apps use my cellular data: turn this off to stop background apps using your plan, or pick which apps can use it.
• Use this SIM for cellular data: if your laptop has both a SIM slot and an eSIM, choose which one to use here.
• Security: turn on Use SIM PIN so no one can use your data if the laptop is stolen. You can also change the PIN or unblock a locked SIM with the PUK code.
• Properties: shows your modem’s IMEI and the SIM’s ICCID. Your operator may ask for these to activate a plan.

If it won’t connect

Some operators need an access point name (APN).

1. In Cellular, select Advanced options.
2. Under APN settings, select Add an APN and type the details from your mobile operator.

Also make sure Airplane mode is turned off. Broader connection problems are covered in fixing Wi-Fi and network problems in Windows 10.

More fixes if cellular won’t work

• There’s no Cellular page in Settings. The laptop probably doesn’t have a cellular modem, even if it has a card slot. Right-click Start, open Device Manager, and expand Network adapters. You should see an adapter with Mobile Broadband, WWAN, or LTE in its name.
• It says “No SIM.” Shut down the laptop, take the SIM out, and reinsert it with the cut corner facing the way the slot’s diagram shows. If you’re using a nano SIM in a larger adapter, make sure it’s seated flat.
• It asks for a PIN. Your SIM is locked. In Cellular > Advanced options, enter the SIM PIN from your operator. Three wrong tries lock the SIM, and you’ll need the PUK code from your operator.
• It connects but has no internet. Check that your plan includes data and hasn’t run out, and double-check the APN details with your operator.
• Still nothing. Download the latest modem driver or firmware from your laptop maker’s support site. Some modems only work with certain carriers or frequency bands.

Frequently asked questions

Can I share the laptop’s cellular data with my phone?

Yes, with Mobile hotspot. Setup takes a few settings, shown in turning on Mobile hotspot in Windows 10.

Does it use Wi-Fi first?

Yes. Windows uses Wi-Fi when it’s connected and switches to cellular when it isn’t.

Can I use my phone’s SIM card in the laptop?

Physically, yes, if it fits and the laptop isn’t locked to another carrier. But many phone plans don’t allow use in a laptop, or treat it as hotspot data. A separate data-only SIM is usually cheaper and simpler.

Every cellular option is described in Microsoft’s Cellular settings in Windows.