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Virtual Landline for UK Businesses
Get a UK virtual landline and answer business calls on your existing mobile for just £5/month+VAT — no app, no VoIP and no engineer visit.
Your Landline Number. On Your Mobile.
ONSIM gives you a UK virtual landline so you can run your business from anywhere. No engineer visits, no PBX, no VoIP headaches — just a proper business number that rings on your existing mobile phone.
Virtual Landline on Your Mobile
Pick a local UK landline number (01, 02) or national (03) and receive calls directly on your existing mobile. No hardware, no office line, no fiddly setup.
Simple, Fast Setup
Pick a number, enter the mobile you want your calls diverted to and our systems do the rest. You can be live in minutes. If you have a supported device, we can also provide a SIM/eSIM so you can tell when it is a business call.
No App. No VoIP Dropouts.
ONSIM Virtual Landline runs at network level in both divert and SIM mode, not through an app. That means more reliable call quality and a simpler experience on mobile.
Upgrade Path to Landline SIM
Start with a simple virtual landline, then upgrade to our Landline SIM if you want to make outbound calls showing your landline number, without moving to VoIP.
6,500+
Customers
What is a virtual landline?
A virtual landline is a UK landline number that rings somewhere other than a fixed desk phone. For most small businesses, that usually means one of three things: calls are forwarded to a mobile, handled through a VoIP app, or delivered natively through a SIM/eSIM.
The important part is not the label. It is how the calls are delivered. That affects reliability, setup effort, call quality and whether you can later make outbound calls showing your landline number.
Why businesses choose ONSIM Virtual Landline
- Look more established: use a proper UK landline number instead of giving out a personal mobile.
- Work from anywhere: answer calls on your existing mobile without being tied to a desk or office line.
- Keep setup simple: no PBX, no engineer visit, no app rollout, no complicated phone system.
- Stay flexible: start with simple inbound call handling, then upgrade if your business needs more.
What is included
- From £5/month + VAT for a UK virtual landline.
- 01, 02 and 03 numbers available, including local and national options.
- Up to 2,500 forwarding minutes, or 5,000 in SIM/eSIM mode, subject to fair usage.
- Fast setup so you can start receiving calls in minutes.
Virtual landline vs VoIP
Many businesses searching for a virtual landline do not actually want a full VoIP phone system. They want a professional number that rings on their mobile without app friction, data dependency or a complex setup.
| Feature | ONSIM Virtual Landline | Typical VoIP/app setup |
|---|---|---|
| Works without an app | Yes | Usually no |
| Best for mobile-first businesses | Yes | Not usually |
| Reliance on data or Wi-Fi for calls | No | Yes |
| Setup complexity | Low | Usually higher |
| Ideal use case | Sole traders, small businesses, mobile teams | Desk-based teams needing more advanced phone system features |
Want the full category breakdown? Read our virtual landline guide.
Virtual Landline vs Landline SIM
Virtual Landline is the right choice if you mainly want inbound business calls to ring on your mobile with the least effort and lowest cost.
If you also want to make outbound calls showing your landline number, or you want a more native business-calling setup on mobile, the better fit is ONSIM Landline SIM.
Best for
- Virtual Landline: inbound calls, professional presence, simplest setup, lower monthly cost.
- Landline SIM: inbound and outbound landline identity, stronger work/personal separation, better long-term mobile workflow.
FAQs
Frequently Asked Questions
Everything you need to know about getting a UK virtual landline with ONSIM.
What is a virtual landline?
A virtual landline is a UK landline number (01, 02 or 03) that is not tied to a physical phone line. With ONSIM, calls can either divert to your existing mobile or be answered using one of our Landline SIMs on a supported device.
How does ONSIM’s virtual landline work?
We give you a UK landline number and route incoming calls to your mobile. If you have a supported device, we can also provide a SIM/eSIM so you can answer calls natively and see when it is a business call. No new hardware or app required.
Who is a virtual landline best for?
A virtual landline is ideal for sole traders, startups, small businesses and mobile teams that want a professional UK number without paying for a traditional office phone system.
Can I keep my existing landline number?
Yes. You can port your current landline number to ONSIM so calls ring on your mobile, desk phone or both. Number porting is a separate one-off charge and is not included in the monthly subscription.
Can I choose my own landline number?
Yes. You can choose from local area codes (01 or 02), national 03 numbers and memorable numbers for a one-off setup fee.
Do I need an app?
No. In divert mode your calls are simply forwarded to your existing mobile number. In SIM mode you can install the SIM/eSIM on a supported device and answer calls directly on your mobile.
What are the differences between divert mode and SIM mode?
In divert mode, calls are forwarded to your existing mobile. In SIM mode, you install an ONSIM SIM/eSIM on a supported device and answer business calls natively on the handset. SIM mode is particularly useful if you want a clearer separation between personal and business calls.
What are the benefits of SIM mode?
With SIM/eSIM mode you can see when a call is for your business without answering, handle calls more professionally and move more easily to outbound caller ID using your landline number. In our view it is the better long-term setup if you have a supported device.
Can I make outbound calls showing my landline number?
Not on the basic Virtual Landline service. If you want outbound calls to show your landline number, upgrade to our ONSIM Landline SIM solution.
Is call quality reliable?
Yes. Calls are carried over standard UK mobile networks, so quality is as good as your normal mobile reception. Because it is not app-based VoIP, you are not relying on Wi-Fi or mobile data for voice calls.
How quickly can I get started?
Setup is fast. Choose your number, enter the mobile you want calls routed to and your virtual landline can be live in minutes.
What does it cost?
ONSIM Virtual Landline costs £5/month + VAT and includes up to 2,500 forwarding minutes, or 5,000 if you use SIM/eSIM mode, subject to fair usage. If you later want outbound calling from your landline number, you can upgrade to Landline SIM.
Is there a fee to port out my virtual landline?
Yes. There is a £20 + VAT fee to port an ONSIM virtual landline number out to another provider.
Can I tell if it is a business call before I answer?
Yes, if you use an ONSIM SIM/eSIM on a supported device. That gives you a cleaner business-call experience than services that rely on a whisper message after you answer.
Virtual landline resources
Researching options? Use these pages to compare providers, understand how virtual landlines work and decide whether you need simple call forwarding or a more advanced mobile-first setup.
Get a UK Virtual Landline Today
Join the thousands of businesses already using ONSIM Virtual Landline to answer calls on their existing mobile, without apps or VoIP.
Learn more about business calling, virtual numbers and mobile productivity
View all posts »Explore the ONSIM blog for practical guides on business numbers, work-life separation, WiFi Calling, roaming and more.
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6,500+
Customers
4.53m
Monthly Calls
12
Years of Service
39
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