Virtual Landline for UK Businesses

Get a UK virtual landline and answer business calls on your existing mobile for just £5/month+VAT — no apps, no VoIP.

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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 tiered minute plans

Simple Fast Setup

Just pick a number, enter the phone number you want your calls diverted to and our automated systems do the rest. You'll be up and running in minutes with a real UK landline number. If you have a supported device we can also provide a SIM/eSIM to answer calls so you can see when it's a business call.

No Apps. No VoIP Dropouts.

ONSIM Virtual Landline service runs at network level (in both divert and SIM mode), not over apps. That means reliable call quality without apps on every call.

Your Number Forever

If you want to move to another phone provider (or upgrade to our Landline SIM) you can take (port) your virtual landline with you. Although it's virtual, an ONSIM Virtual Landline number is a real UK landline number so can be used with any UK provider.

5,000+

Business Customers

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 normal UK landline number (01, 02 or 03) that eiter diverts calls to your existing mobile or allows you to answer on one of our unique Landline SIM's. It lets you look professional and stay reachable without needing a physical line or broadband.

How does ONSIM’s virtual landline work?

We give you a local UK landline number that either forwards all incoming calls to your mobile or we can provide you with a SIM/eSIM to answer calls if you have a supported device. You don’t need any new hardware or apps.

Can I keep my existing landline number?

Yes. You can port your existing landline number to ONSIM so your customers keep calling the same number — it just rings on your mobile instead of (or as well as) a desk phone.

Can I choose my own landline number?

Absolutely. You can choose from local area codes (01 or 02), national 03 numbers, or even memorable numbers for a one-off setup fee.

Do I need an app?

No apps needed. In divert mode your calls are simply forwarded to your existing mobile number. Just answer as normal. In SIM mode you can install the SIM/eSIM on a supported device and answer calls on your mobile.

What are the differences between Divert and SIM mode?

No differences in price. 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 on the mobile. This works really well in devices that support dual SIM.

What are the benefits of SIM mode?

If you install the SIM/eSIM you can see instantly (without answering the call) that it's a business call, choosing whether to answer and making sure you always answer the call professionally. You also have more control over routing and can easily upgrade to be able to make outbound calls displaying your landline number. In our opinion it's a superior service, but it takes a little more effort to set up and you must have a supported device.

Can I make outbound calls showing my landline number?

Not with the basic Virtual Landline service. To display your landline when calling out, upgrade to our ONSIM Landline SIM solution.

Is call quality reliable?

Yes — calls are carried over standard UK networks, so quality is as good as your normal mobile reception. Because it’s not VoIP or an App, you’re not relying on Wi-Fi or mobile data for voice calls.

How quickly can I get started?

Setup is simple and instant. Choose your number, enter the mobile you want calls forwarded to, and your new virtual landline will be live instantly. We think this is the simplest Virtual Landline setup process in the world.

What does it cost?

ONSIM’s virtual landline is one of the cheapest and simplest in the UK — pay £5 per month + VAT for up to 2,500 forwarding minutes or 5,000 if you use SIM/eSIM mode (the fair usage policy) - as a small business you shouldn't need more inbound minutes than that. You can upgrade anytime to our full Landline SIM for to make outbound calls from your number.

Who is this service for?

Perfect for sole traders, startups, and small businesses that want a professional UK landline number without the cost or complexity of traditional telecoms.

Can I tell if it's a business call without answering the call?

If you have a supported device you can install an ONSIM SIM/eSIM so you can tell if it's a business or personal call without answering. Other Virtual Landlines make you answer the call to hear a recording telling you if it's a work call (often called a call 'whisper').