How to Divert Calls from Landline to Mobile UK: Codes & Steps

Need to divert calls from your landline to a mobile? Whether you're working remotely, out of the office, or simply want to ensure you never miss an important business call, call diversion is a straightforward solution. This guide covers the exact codes and steps for all major UK providers, plus a smarter long-term alternative for businesses.

How to Divert Calls from a BT Landline to Mobile

BT is the most widely used landline provider in the UK, and their call diversion codes are simple to use. Pick up your BT landline handset and dial the following:

BT Call Divert Codes

• Divert all calls: Dial *21*[mobile number]# then press the call button. You'll hear a confirmation tone.
• Divert unanswered calls (after ~15 seconds): Dial *61*[mobile number]#
• Divert when line is busy: Dial *67*[mobile number]#

To cancel call diversion on BT:

• Cancel all diverts: Dial #21#
• Cancel unanswered diverts: Dial #61#
• Cancel busy diverts: Dial #67#

Replace [mobile number] with the full UK mobile number you'd like to forward calls to (e.g., *21*07700900123#).

Call Divert Codes for Sky, TalkTalk & Plusnet

Most UK landline providers use the same standard divert codes as BT, since they operate on the Openreach network. Here's a quick reference:

Note: Virgin Media operates its own cable network, so some features may need to be activated via their online portal or customer services before the star codes work.

How to Divert Calls on a VoIP Phone System

If your business uses a hosted VoIP (Voice over IP) phone system, call diversion is typically much more flexible and can be managed without dialling codes at all. Here's how it usually works:

1. Log in to your VoIP admin portal — most hosted phone systems provide a web-based dashboard or app.
2. Navigate to call routing or call forwarding settings — this is usually found under your extension or user settings.
3. Enter the mobile number you wish to forward calls to and select the diversion type (all calls, unanswered, busy, or out-of-hours).
4. Save your changes — the divert takes effect immediately with no need to touch the handset.

With VoIP, you can also set up advanced rules such as time-based routing (e.g., divert to mobile after 5:30pm), sequential ringing across multiple devices, or simultaneous ring on desk phone and mobile. This level of control simply isn't available with traditional landline diversion.

How Much Does Landline-to-Mobile Diversion Cost?

This is where many businesses get caught out. When you divert calls from a traditional landline to a mobile, you pay for every diverted call — not the caller. The charges are typically:

• BT: Diverted calls are charged at BT's landline-to-mobile rate, which can be up to 15p–17p per minute outside inclusive call plans.
• Sky / TalkTalk / Plusnet: Similar rates apply. Calls diverted to mobiles are rarely included in "free calls" bundles.
• VoIP systems: Costs vary by provider, but many hosted VoIP plans include mobile diversions within bundled minutes — or charge significantly less per minute (often 2p–5p per minute).

For businesses receiving a high volume of calls, these diversion charges can add up quickly. If you're regularly diverting calls, it's worth considering whether a VoIP-based solution would be more cost-effective.

A Better Alternative: Virtual Landline Numbers with VoIP

Rather than diverting a traditional landline, many UK businesses are switching to virtual landline numbers powered by VoIP. Here's why:

• Keep your existing landline number — you can port your current number to a VoIP platform.
• Answer calls anywhere — use a mobile app, laptop, desk phone, or all three simultaneously.
• No diversion charges — because calls route over the internet, there's no separate landline-to-mobile forwarding cost.
• Professional features — auto-attendant, voicemail-to-email, call recording, hunt groups, and more.
• Future-proof — with the BT PSTN switch-off scheduled for January 2027, all traditional landlines will eventually move to VoIP anyway.

A virtual landline gives you all the flexibility of call diversion without the ongoing cost or hassle of star codes.

For a more detailed walkthrough covering every scenario, read our full guide: How to Divert Calls from Landline to Mobile UK — The Complete Guide.