How to Divert Calls from Landline to Mobile UK: Your Complete Step-by-Step Guide
Whether you’re stepping out of the office, working remotely, or simply need to ensure you never miss an important business call, knowing how to divert calls from your landline to your mobile in the UK is essential. Call diversion — sometimes called call forwarding — routes incoming landline calls directly to your mobile phone, keeping you connected wherever you are.
In this comprehensive guide, we’ll walk you through the exact setup process for every major UK provider, explain the costs involved, and show you why modern VoIP solutions offer a far superior — and often more cost-effective — alternative for businesses that rely on permanent call forwarding.
What Is Call Diversion and How Does It Work?
Call diversion is a telephony feature that automatically redirects incoming calls from one number to another. When you divert calls from your landline to your mobile, the caller dials your landline number as normal, but the call rings on your mobile instead. The caller typically doesn’t know the call has been redirected — they simply hear the phone ringing.
There are several types of call diversion available on most UK networks:
- Unconditional diversion: All calls are forwarded immediately, regardless of whether you’re on the phone or not.
- Divert on busy: Calls are only forwarded when your landline is engaged.
- Divert on no answer: Calls forward after a set number of rings if you don’t pick up.
- Divert on unavailable: Calls forward when your line is out of service or disconnected.
For a deeper look at the differences between these options and more advanced configurations, read our full guide on call forwarding for business.
How to Divert Calls from Landline to Mobile: Setup by Provider
The process varies slightly depending on your landline provider. Below, you’ll find step-by-step instructions for BT, Sky, TalkTalk, and Plusnet — the UK’s most popular residential and business landline providers.
BT Call Divert Setup
BT uses standard star codes dialled directly from your landline handset. Here’s how to set up each type of diversion:
- Divert all calls: Pick up your handset and dial
*21*[mobile number]#— for example,*21*07700900000#. You’ll hear a confirmation tone. - Divert on no answer: Dial
*61*[mobile number]# - Divert when busy: Dial
*67*[mobile number]#
To cancel call diversion on BT:
- Cancel all-call divert: Dial
#21# - Cancel no-answer divert: Dial
#61# - Cancel busy divert: Dial
#67#
Sky Call Divert Setup
Sky Talk uses the same star code system as BT for call diversion:
- Divert all calls: Dial
*21*[mobile number]# - Divert on no answer: Dial
*61*[mobile number]# - Divert when busy: Dial
*67*[mobile number]#
Cancellation codes are identical to BT. You can also manage some diversion settings through the Sky customer portal or by contacting Sky’s customer service team.
TalkTalk Call Divert Setup
TalkTalk also supports the standard divert codes:
- Divert all calls: Dial
*21*[mobile number]# - Divert on no answer: Dial
*61*[mobile number]# - Divert when busy: Dial
*67*[mobile number]#
To deactivate, use the corresponding #21#, #61#, or #67# codes. TalkTalk customers should note that call divert may need to be activated on your account first — check your My Account dashboard or ring TalkTalk support.
Plusnet Call Divert Setup
Plusnet, which operates on the BT Openreach network, uses the same codes:
- Divert all calls: Dial
*21*[mobile number]# - Divert on no answer: Dial
*61*[mobile number]# - Divert when busy: Dial
*67*[mobile number]#
Plusnet customers can also manage call features through the Plusnet Member Centre. Cancellation follows the same # codes outlined above.
How Much Does Landline Call Diversion Cost in the UK?
This is where many businesses get caught out. While setting up call diversion is usually free, you will be charged for every diverted call. The costs can add up quickly, particularly if you receive a high volume of calls.
| Provider | Diversion Cost | Notes |
|---|---|---|
| BT | Standard call rates to the mobile number | Not included in calling plans; charged per minute |
| Sky | Standard call rates to the destination number | Diverted calls use your call allowance or are charged at standard rates |
| TalkTalk | Standard mobile call rates apply | Calls to mobiles are typically not included in free call packages |
| Plusnet | Standard call rates to mobiles | Check your plan for mobile minute allowances |
As a rough guide, landline-to-mobile call charges across these providers typically range from 10p to 20p per minute. For a business receiving 50 diverted calls per day, each averaging three minutes, that could equate to £15–£30 per day — or upwards of £400–£600 per month.
This ongoing expense is one of the primary reasons growing businesses explore VoIP-based alternatives.
Why VoIP Is the Smarter Alternative for Business Call Diversion
Traditional call diversion is a quick fix, but it was never designed for businesses that need permanent, flexible call routing. If you’re regularly diverting landline calls to mobiles — or to multiple team members — a hosted VoIP (Voice over IP) phone system is a far more powerful and cost-effective solution.
Key Advantages of VoIP Over Traditional Call Diversion
- No per-minute diversion charges: VoIP calls route over the internet, meaning forwarding to mobiles, softphones, or other devices is typically included in your plan at no extra cost.
- Use your business number anywhere: Answer calls on your desk phone, mobile app, laptop, or tablet — all from your existing business number.
- Advanced call management: Set up ring groups, hunt groups, auto-attendants, time-based routing, and voicemail-to-email — features traditional landlines simply cannot match.
- Scalability: Add or remove users in minutes, without engineers or hardware changes.
- Professional image: Callers always see your business number, not a personal mobile — and you can manage every aspect from an online portal.
Connection Technologies’ HyperCloud hosted VoIP platform is built specifically for UK businesses that need reliable, feature-rich telephony without the limitations and costs of traditional landline diversions. With HyperCloud, your team can take business calls on any device, from any location — with crystal-clear call quality and enterprise-grade security.
Ready to Ditch Expensive Call Diversion?
If you’re paying to divert landline calls to mobiles every day, it’s time to consider a hosted VoIP solution that gives you total flexibility at a fraction of the cost. Connection Technologies can design a bespoke system tailored to your business.
When Should You Use Traditional Call Diversion vs. VoIP?
Traditional landline call diversion still has its place — it’s ideal as a temporary, short-term measure. For example:
- You’re moving offices and need calls routed for a few days.
- A staff member is out of the office unexpectedly and needs calls redirected immediately.
- You’re testing whether remote working is viable before committing to a new phone system.
However, if call diversion is something you rely on daily or weekly, the costs and limitations of traditional forwarding make VoIP the clear winner. Connection Technologies regularly helps businesses make this transition smoothly, porting existing numbers and configuring systems with minimal disruption.
Speak to our team about transitioning from landline diversion to VoIP →
Frequently Asked Questions
Pick up your BT landline handset and dial *21* followed by your mobile number, then #. For example: *21*07700900000#. You’ll hear a confirmation tone indicating the diversion is active. To cancel, dial #21#. Note that you’ll be charged standard landline-to-mobile rates for each diverted call.
Yes. While activating call diversion is generally free, each diverted call is charged at your provider’s standard landline-to-mobile rate — typically between 10p and 20p per minute. These charges are billed to the landline account holder, not the caller. Calls to mobiles are usually excluded from inclusive call packages.
Technically yes — the unconditional divert (*21*) remains active until you cancel it. However, permanent diversion via a traditional landline can be very expensive due to per-minute charges. For permanent call routing, a hosted VoIP solution like Connection Technologies’ HyperCloud is far more cost-effective and feature-rich, allowing you to receive calls on your mobile, laptop, or desk phone at no additional forwarding cost.
Yes. The standard star codes (*21*, *61*, *67*) work across BT, Sky, TalkTalk, and Plusnet, as all of these providers operate on the BT Openreach network. The cancellation codes (#21#, #61#, #67#) are also identical across these networks.
Hosted VoIP is widely considered the best alternative. A VoIP system allows you to receive business calls on any internet-connected device — including mobiles, laptops, and desk phones — without incurring per-minute diversion charges. It also provides advanced features such as auto-attendants, ring groups, call recording, and time-based routing that traditional landlines cannot offer. Connection Technologies specialises in hosted VoIP for UK businesses.
In most cases, no. The caller simply hears the phone ringing as normal and won’t be aware the call has been redirected. However, they may notice a slight delay in the call connecting. With a VoIP system, this is handled even more seamlessly, as calls are routed natively to whatever device you’re using — there’s no traditional “diversion” taking place.