Your IP address changes when your internet service provider assigns you a new one, which happens most often when you restart your modem or router, switch providers, or move to a new location.

Every device connected to the internet has an IP address — a unique number that identifies it on the network. Your home internet connection gets one from your internet service provider (ISP). That address is not permanent. It can change for several straightforward reasons, and understanding when and why helps you troubleshoot connection problems or know what to expect if you need a stable address for work or gaming.

The change usually happens without you doing anything. Your ISP can reassign addresses automatically, or your equipment can request a new one. Sometimes you trigger the change yourself by restarting hardware. In rare cases, you might want to prevent the change — for instance, if you run a home server or need a consistent address for remote access.

Key Takeaways

  • Restarting your modem or router is the most common reason your IP address changes, because the device requests a fresh address from your ISP when it reconnects.
  • Your ISP can change your address automatically on a schedule (often every 24 to 30 days) even if your equipment never restarts.
  • Switching internet providers, moving to a new address, or changing from mobile to home internet will always result in a different IP address.
  • A static IP address — one that does not change — is available from most ISPs but usually costs extra per month.
  • Knowing your current IP address takes seconds and can help you diagnose network problems or set up remote access to your devices.

Why your modem restart changes your IP address

When you power off your modem and turn it back on, it reconnects to your ISP's network and requests a new address. This is the single most common reason for a change. Your modem uses a system called DHCP (Dynamic Host Configuration Protocol) to ask the ISP's server for an address each time it boots up. The server usually assigns a different one, though occasionally it may hand back the same address if it is still available.

Restarting your router separately does not usually change your IP address, because the router gets its address from the modem. The modem is what talks directly to your ISP. If you restart only the router, your modem stays connected and keeps its address.

This is why tech support often asks you to restart your modem first when you have connection trouble. The restart forces a fresh connection and can clear temporary glitches. As a side effect, you get a new IP address.

How ISPs assign and rotate addresses automatically

Your ISP does not hold onto your address forever. Most providers use a lease period — typically 24 to 30 days — after which your modem must renew its address. When the lease expires, your ISP's server may assign you a different address from its pool, even if your modem never restarts. You will not notice this happening; it occurs in the background.

Some ISPs set longer lease periods (up to 90 days or more), and a few set shorter ones. The exact period depends on your provider and your service plan. You can check your modem's settings to see the lease time remaining, though most people never need to.

This rotation system exists because ISPs have a limited pool of addresses to distribute among all their customers. By recycling addresses, they can serve more people than they have addresses available. If you stay offline for a while, your address goes back into the pool for someone else to use.

When you switch providers or move

Changing internet providers always means a new IP address, because you are now connecting through a different company's network. Your old ISP's address becomes useless the moment your service ends. The new provider assigns you an address from their own pool.

Moving to a new location — even if you keep the same ISP — often results in a different address. The ISP may route you through a different regional server or have different address pools for different areas. You cannot assume your address will stay the same.

If you switch from a wired home internet connection to mobile internet (like a phone hotspot or mobile broadband), you will definitely get a different address. Mobile networks assign addresses from their own separate pools.

Getting a static IP address if you need one

If you run a home server, host a website, or need remote access to a device on your network, a changing IP address becomes a problem. You cannot reliably point people to a moving target. Most ISPs offer static IP addresses — addresses that do not change — but they charge a monthly fee, usually between $5 and $15 depending on the provider.

To request a static address, contact your ISP directly. You will typically need to upgrade your service plan or add it as an option. The ISP will assign you an address and configure your account so that address stays with you indefinitely, or until you cancel the service.

Static addresses are more common on business plans than residential ones. If you have a residential account and need stability, check whether your ISP offers static IP as an add-on before assuming you have to switch to a business plan.

How to find your current IP address

You can find your IP address in seconds using a web browser. Visit a site like whatismyipaddress.com or straightforward search "what is my IP" in any search engine. The site will display your public IP address — the one your ISP assigned to your modem, which is visible to the rest of the internet.

If you need your device's local IP address (the one it uses within your home network), the method depends on your device. On Windows, open Command Prompt and type ipconfig. On Mac or Linux, open Terminal and type ifconfig. On a phone or tablet, go to Settings, then Network or Wi-Fi, and look for IP Address in the connection details.

Knowing both numbers is useful. Your public IP is what websites see. Your local IP is what your router uses to send data to your specific device at home.

What happens if your address changes unexpectedly

If you notice your IP address has changed and you did not restart anything, your ISP likely renewed your lease or rotated your address automatically. This is normal and requires no action on your part. Services and websites will continue to work normally.

If you were relying on a static address for remote access or port forwarding, an unexpected change will break that connection. You would need to update the address in your remote access software or firewall rules. This is one reason people pay for static IPs — to avoid this disruption.

If your address changes frequently and you have not set up a static IP, consider whether you actually need stability. Most home users never notice or care about address changes because they only browse the web and use apps, which do not depend on a fixed address.

Frequently Asked Questions

Can I keep my IP address from changing?

Yes, by purchasing a static IP address from your ISP. This typically costs $5 to $15 per month and locks your address in place. Without paying for static IP, your address will change periodically as part of normal ISP operations.

Does restarting my router change my IP address?

Restarting only the router usually does not change your IP address. The modem is what connects to your ISP and holds the address. Restart the modem if you want to trigger a new address. Restarting the router clears its memory but does not affect the modem's connection.

How often does my IP address change?

Most ISPs renew addresses every 24 to 30 days, though some use longer or shorter periods. Your address can also change if you restart your modem, switch providers, or move. Without a static IP, expect changes to happen periodically.

Will my internet stop working if my IP address changes?

No. Address changes happen automatically and your internet continues to work. The only exception is if you set up port forwarding or remote access using your old address — those connections will break and need to be updated with the new address.

Is my IP address the same on all my devices?

No. Your modem has one public IP address (assigned by your ISP), but each device on your home network gets its own local IP address from your router. Websites see only your modem's public address. Your devices use local addresses to communicate with each other and the router.