Reseller Portal

Can VoIP Numbers Be Ported?

It is your unconditional right to transfer your telephone numbers from one supplier to another, whatever your reasons are, such as: seeking better contract conditions, cheaper packages, or a better customer service.

In this article, we will explain how to do this and what challenges might arise in the porting process.


Number porting in the UK is regulated by Ofcom.   Their general rule is that you are always free to port your telephone numbers to a new service provider whenever you wish. This rule has been written in Ofcom General Conditions of Entitlement, which states that all UK numbers must be portable and customers must always have the right to move their numbers to a new provider.

Your existing service provider is not allowed to refuse your porting request – even if you are still in a contract with them, and even if you are in dispute with them – as long as the numbers are working.

How to port your numbers?

The process of porting numbers must be managed by your new service provider. It is their responsibility to request the numbers from the “losing provider”.   All you need to do is sign a standard Letter of Authority which gives the new provider your permission to take over your numbers.

You shouldn’t end your current contract before porting your telephone numbers because your existing service provider could take the numbers out of service, then the numbers will not be portable.

VIP VoIP provides a fully managed service for porting customers’ numbers to our network.

How long will it take to port my numbers?

Porting a single VoIP number to a new provider should usually take seven days, if the information provided on the Letter of Authority is accurate, and if the losing provider doesn’t drag their feet.   More complicated port requests with multiple numbers might take two or three weeks to complete. Meanwhile, your numbers will stay live and working with your current VoIP provider until the agreed porting date. The transition from an old provider to a new provider is usually almost instantaneous.

Can my current provider refuse to port my numbers away?

Ofcom does not allow service providers to block number port requests, but sadly, there are still many unethical companies who try to work around Ofcom’s rules. They won’t explicitly refuse your request to port your VoIP numbers, but they put up obstacles and make it very difficult. They will try and bully you into staying with them or they might demand a payment to port your numbers.

If that happens, you should not hesitate to remind them of their legal obligations and, if necessary, report their actions and seek help from Ofcom.

VIP VoIP is an ethical supplier. We will never make it difficult for you to move your services to another supplier, and if you are planning to transfer your services to our network, we will not rest until the job is done.

Get in touch with us today by calling us on 03300881182 or sending an email to

What are the possible issues with number porting?

The two most common reasons for a number porting request to be delayed are:

  1. A mismatch between your current business address and the address which BT recognises as the “service address” for the number on their national database. If that happens, your new service provider will ask you to contact your existing provider to correct the problem.
  2. You might have additional numbers on your account (possibly forgotten), which are associated with your main number.  If these numbers are not referenced on your Letter of Authority, the port request will be rejected.  In that case, your new service provider will ask you to confirm what you want to do with the additional numbers.

Another problem which can sometimes happen (although rarely) with numbers which are ported from traditional analogue or ISDN lines, is occasional incoming call failures.   These numbers remain attached to their original BT exchange, and software in the exchange has to reroute incoming calls to the new VoIP service provider.   This rerouting mechanism can sometimes fail and there is nothing the VoIP provider can do to fix the problem, other than report it to BT.