When ordering a business internet connection, you will often be offered a static IP address as an optional extra. Is it worth paying for? The answer depends on whether anyone needs to find your network from the outside. This guide explains static vs dynamic IP addresses, both on the internet side and inside your office, and when each makes sense.
Two places the question comes up
"Static or dynamic" applies to two different addresses, and mixing them up causes confusion:
- Your public IP address, assigned by your internet provider to your router. This is how the internet sees your whole office.
- Each device's private IP address on your internal network, assigned by your router or a server.
We will cover both, starting with the one you usually pay for.
Dynamic public IP addresses
A dynamic address is leased to your router automatically and can change: after a router restart, after a period of time, or when the provider reorganizes its network. Most home and many small-business connections are dynamic by default.
Advantages: no extra cost, no configuration, and a changing address makes your connection slightly harder to track over long periods.
Disadvantages: anything that relies on "our office IP" breaks when it changes. Allow-lists, remote access setups and hosted services may suddenly lock you out.
Some providers also place customers behind carrier-grade NAT, where many customers share one public address. In that case you do not have a public address of your own at all, and nobody can connect inbound to your network.
Static public IP addresses
A static address is permanently assigned to your connection and does not change unless you change providers or plans. Providers usually charge extra for it, either per address or for a small block such as a /29.
When a static IP address is genuinely useful
- IP allow-listing. Your bank, payment gateway, cloud database or a supplier's portal only accepts connections from approved addresses. With a static IP, you add it once.
- Hosting services on-site. A VPN server, a security camera recorder or a self-hosted application that external users need to reach consistently.
- Site-to-site VPNs. Many VPN configurations are simpler and more reliable when both ends have fixed addresses.
- Running a mail server on-site. Outgoing mail needs a stable address with matching reverse DNS (a PTR record) to avoid being treated as spam. This also requires the provider to set reverse DNS for you and not block port 25. For most businesses, hosted email is a better choice anyway.
When you probably do not need one
- Your website and email are hosted elsewhere (shared hosting, cloud, Microsoft 365, Google Workspace).
- Staff only browse the web and use cloud apps.
- Remote workers connect to cloud services rather than to the office.
To see your current public address, and check later whether it has changed, use What Is My IP.
Alternatives to paying for a static IP
- Dynamic DNS (DDNS). A small client on your router or a computer updates a DNS hostname, such as
office.example.com, whenever your address changes. Users connect by name instead of number. Many routers support DDNS providers built in. It does not help with services that only accept fixed IP allow-lists. - A cloud VPN or gateway with a fixed address. Staff and office traffic route through a small cloud server or managed gateway that has a static IP. Suppliers allow-list that one address, wherever your staff actually are. This also works well for remote teams.
- Move the service to the cloud. If you only need a static IP to host one application on-site, hosting it with a cloud provider may be simpler and more reliable than exposing your office network.
Static vs dynamic IP inside your network
Inside the office, devices usually get their private addresses from a DHCP server, typically built into the router. DHCP (Dynamic Host Configuration Protocol) hands out an address from a pool along with the gateway and DNS server settings, and the lease is renewed periodically.
Some devices should keep the same address so others can find them: printers, network storage, servers, access points and cameras. There are two ways to do this:
| Method | How it works | Pros and cons |
|---|---|---|
| DHCP reservation | The router always gives a particular device (identified by its MAC address) the same address | Managed centrally; easy to change later. Recommended for most devices. |
| Manual static configuration | The address, mask, gateway and DNS are typed into the device itself | Works even if DHCP is down; but easy to create conflicts and forget about. Best for core infrastructure such as routers and DHCP servers. |
If you do set manual addresses, keep them outside the DHCP pool. For example, let DHCP hand out 192.168.1.100 to .200 and reserve .2 to .50 for manually configured equipment. Otherwise the router may eventually hand the same address to a laptop, and two devices will fight over it. A subnet calculator helps you plan these ranges on larger networks.
Security considerations
A static public IP is not inherently less secure, but it is a stable target. Anything you expose on it will be found by internet-wide scanners, usually within hours. If you take a static IP to host services, make sure only the ports you intend are open, keep those services patched, and restrict administrative access to a VPN.
Key takeaways
- Dynamic public IPs are fine for offices that only use cloud services and browse the web.
- Static public IPs are worth it for allow-listing, site-to-site VPNs and on-site services.
- Dynamic DNS and cloud gateways can replace a static IP in many situations.
- Inside the network, prefer DHCP reservations for printers and servers, and keep manual addresses outside the DHCP pool.