Can I Keep My Business Number When Switching From Landline to VOIP?

By Olivia Johnson - Trusted UK Business Expert

Last Updated 12th of January 2026

6 minute read

Switching your business phone from a traditional landline to a modern VOIP system might seem complex, but it’s easier than you think. Many UK businesses move to VOIP to save costs and gain flexibility — all while keeping their trusted phone numbers. We’ll explain how to do it safely and smoothly.

You can usually keep your business number when switching from a landline to VOIP. The process, called number porting, transfers your existing number from your current landline provider to your new VOIP service, ensuring you stay reachable without disruption.

In this guide, you’ll learn exactly how number porting works, what steps to take before switching, and what to expect during the transition. Keep reading to make sure your move to VOIP is smooth and your business number stays secure.

Click the button below to see how easy it is to move your business number without any disruption.

Understanding Number Porting When Moving from Landline to VOIP

When you switch from a traditional landline system to a VOIP (Voice over Internet Protocol) service, one of the most common questions is whether you can keep your existing business number. The good news is that, in most cases, you can. This process is known as number porting — it allows your existing number to be transferred to a new service provider.

This process is governed by Ofcom, the UK communications regulator, which ensures that customers can keep their phone numbers when changing providers. VOIP systems work digitally, using your internet connection instead of a copper phone line. This means your number isn’t tied to a physical location, giving your business more freedom and flexibility than before.

Keeping your existing number is not only convenient but also important for maintaining brand consistency. Your customers already know your number — changing it could lead to missed calls or lost sales. By porting your number, you can keep your professional image while benefiting from lower call costs and more advanced features.

How Number Porting Works in the UK

Number porting involves a few key steps that your VOIP provider manages on your behalf. Here’s how it typically works:

• Choose a VOIP Provider: Find a VOIP provider that supports number porting. Most reputable UK providers do, but it’s always best to confirm before signing a contract.
• Submit a Porting Request: Your new provider will ask you for details about your current phone line — including your existing number, account number, and the name of your current provider.
• Authorisation Process: You’ll need to sign a Letter of Authorisation (LOA) that allows your new provider to request the number transfer on your behalf.
• Porting Approval: The current provider will review and approve the request. This step usually takes between 5 to 10 business days.
• Switch Completion: Once approved, your number is transferred to your new VOIP system. There’s minimal downtime — most providers complete the switch within a few hours.

Your business can continue using the same phone number seamlessly after the transfer is done.

Benefits of Keeping Your Business Number

There are several practical reasons to keep your business number when switching to VOIP:

By keeping your number, you maintain your business reputation and continuity while moving to a more flexible and modern communication system.

Things to Check Before Switching to VOIP

Before starting the porting process, there are a few important things to confirm:

• Contract Terms: Check if your current landline contract has any exit fees or minimum terms.
• Compatibility: Make sure your VOIP system supports the number format (e.g. local or non-geographic numbers).
• Internet Quality: VOIP depends on a stable internet connection. Test your connection speed to ensure clear calls.
• Emergency Services: Verify that your VOIP system supports 999 calls if needed.
• Backup Plan: Some businesses use call forwarding during the transition to avoid downtime.

By preparing in advance, you’ll ensure a seamless transfer with no interruption to your business communications.

What Happens During the Porting Process?

The number porting process usually happens behind the scenes. However, it’s useful to understand what to expect:

• Temporary Downtime: Your number might be unavailable for a short time (typically under an hour) while the switch completes.
• Testing Period: Once ported, test inbound and outbound calls to confirm the number works as expected.
• Old Line Deactivation: After the number moves to VOIP, your old landline will be disconnected.

If you want to avoid downtime, schedule the porting process during off-peak business hours.

What if I Have Multiple Business Numbers?

Many UK businesses have multiple numbers for different departments or locations. VOIP makes managing these easier.

With most VOIP systems, you can:

• Port all your numbers in a single request.
• Assign numbers to specific teams or call queues.
• Use a virtual receptionist to route calls automatically.

This centralised approach means less admin and better organisation for your business communications.

Can I Keep My Number if I’m Moving Offices?

Yes — and this is one of the biggest advantages of VOIP. Unlike traditional landlines, VOIP numbers are not tied to a specific geographic address. This means you can keep your existing number even if you move to a new city or region in the UK.

This flexibility is ideal for growing businesses or those adopting hybrid work models. Whether your team works from home, a new office, or different locations, everyone can stay connected under the same trusted business number.

Costs Involved in Keeping Your Number

Most providers offer number porting for free, but some may charge a small administrative fee — usually between £10 and £25 per number.

Here’s a quick cost overview:

Always ask your provider for a clear breakdown before proceeding.

Tips for a Smooth Transition to VOIP

• Plan Ahead: Start your porting request well before your current contract ends.
• Choose a Trusted Provider: Look for UK-based providers with Ofcom accreditation.
• Backup Communication: Keep a mobile line active in case of any delays.
• Inform Your Team: Train staff on how to use the new VOIP system before the switch.
• Monitor Call Quality: Once live, monitor your VOIP performance and call clarity.

These steps will help make your transition easy and stress-free.

Why VOIP Is the Future for Business Communications

The UK’s traditional PSTN (Public Switched Telephone Network) is being phased out by 2025, meaning all landline users must switch to digital alternatives like VOIP.

By moving early, your business avoids last-minute disruptions and gains:

• Cheaper Call Costs
• Scalable Communication Tools
• Remote Work Flexibility
• Smart Features like Call Recording and Analytics

Making the move now ensures your business stays ahead of the technology curve.

Common Problems and How to Avoid Them

Even though number porting is straightforward, some issues can occur:

A little preparation can prevent most porting issues before they arise.

Why Businesses Should Act Now

Industry experts recommend that all UK businesses prepare for the switch to VOIP before the PSTN switch-off deadline. Businesses that delay risk losing service or facing urgent migration fees.

VOIP offers greater control, better mobility, and improved collaboration — especially for small to medium-sized enterprises. With the ability to keep your number, there’s no downside to upgrading early.

Ready to switch to VOIP and keep your business number? Click the link below to compare the best VOIP providers in the UK and start your seamless transition today.

FAQ

Can I keep my business number when switching to VOIP?

Yes. You can keep your existing number through a process called number porting, which transfers your current number to your new VOIP provider.

How long does number porting take?

The process typically takes 5–10 working days, depending on your providers.

Will my phone service be interrupted?

There may be a short downtime (usually under an hour), but many providers manage the switch with minimal disruption.

Can I keep my number if I move offices?

Yes, VOIP numbers are location-independent, so you can keep your number anywhere in the UK.

Is VOIP more cost-effective than a landline?

Absolutely. VOIP plans often cost less per month and include features like call forwarding, recording, and conferencing at no extra cost.

Final Thought:

Switching from a landline to VOIP is a smart move for any modern business. With the ability to keep your number, enjoy lower costs, and gain advanced features, VOIP ensures your business is ready for the digital future.

Click below to explore top VOIP solutions and keep your business connected today.