Number Porting

Telephone number porting is the ability to change your service provider whilst keeping your telephone number. Switching phone providers to Callagenix allows you to keep your existing number and use it with our range of services.

Number porting is a relatively straightforward process, but you do need to make sure all the steps are carried out properly. The number porting itself usually happens overnight and there is no loss of service. Should there be a problem during the transfer your number immediately switches back to your existing supplier until it is rectified.

Why port your number to Callagenix?

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  • Take advantage of our rates
  • Take advantage of our wide range of services
  • More control over your number and phone system

When you're changing phone provider it can feel a little daunting at first, but it needn't be anything to worry about. Of course, we'll work with you to make sure it all goes smoothly.

The actual process of porting should take no longer than 7 days provided all the documentation is correct. It is free of charge from Callagenix.

Porting agreements

Callagenix can port any UK BT local geographic numbers starting with 01xx & 02xx, plus any non-geographic number starting with 08xx, 03xx and 09xx from the following carriers:

 BT, Cable & Wireless, (including Energis) Thus, Telewest, Kingston (formerly Torch), Your Communications (formerly Norweb), NTL/Virgin Media, Verizon (formerly MCI WorldCom)

To check who your number is with, please click here Phonecodeinfo

How to port your number

Porting your number to us is a quick and fairly painless process if all the documentation provided is correct. The porting process for Geographic 01xx or 02xx numbers, and Non-Geographic 08xx, 03xx or 09xx numbers is pretty much identical, apart from the documents needed.

General Process

  • You will need to open a Callagenix account if you have not done so already (register here). We use your Callagenix account ID to tie up all documentation and required service set-up information.
  • Scan and email (or fax) all the required and completed porting documents.  Please email to, or fax to 0333 247 0001 quoting your Callagenix account ID as a reference number.
  • Our porting department will then check all the documentation and send to the loosing carrier if correct.  If accepted by the loosing carrier we will be given a porting date and time.  If not accepted by the loosing carrier, there could be a discrepancy with the documentation provided, or the number.
  • Between the porting acceptance date and the actual port date we setup and test your required number service in readiness for the port to take place.
  • The number port will then take place at the designated time (usually midnight at weekends).  If for whatever reason and in the unlikely event there is an issue with the port, there is a well-established Ofcom process to immediately re-instate the original service and rectify any issues before the port is attempted again.
  • Once ported the relationship with the loosing provider is ceased and you then have full control over your number within your Callagenix account.

Geographic number porting – BT 01xx & 02xx numbers

If you are looking to reduce your line and maintenance costs and take advantage of the flexibility and scalability of our hosted VoIP service, Callagenix can port your local 01xx & 02xx numbers from BT.

GNP Process

  • Assuming you have opened a Callagenix account, in the first instance we will require a copy of your BT bills that relate to the numbers you wish to port.  These can be scanned and emailed to or faxed to 0333 247 0001.
  • We will then part-complete the GNP Letter of Authority document and send it back for you to print and sign on your headed paper. This can then be scanned and emailed to or faxed to 0333 247 0001.
  • We will then check and send to BT to process the port.  During this time we will need to set-up and test your new service prior to the porting date.
  • NB. Important - Once you have committed to porting your number away from BT they will either cancel your telephone line that your number “sits” on, or if required, re-number your telephone line. 

GNP Letter of Authority document

Non-geographic number porting or migrating – 08xx, 03xx, 09xx numbers

If you are looking to reduce your costs or perhaps benefit from better revenue rates, or take advantage of a Callagenix advanced service, why not port your Non Geographic number?

NGNP Process

  • Assuming we have confirmed you can port the number and you have opened a Callagenix account, we will require a copy of your provider's bill that relates to the numbers you wish to port.  This can be scanned and emailed to or faxed to 0333 247 0001.
  • Resellers. In certain cases although the number may belong to your organisation, you may not be the “owner” from a porting perspective.  This is typically the case where a reseller of the main carrier is involved.  In this instance the reseller will need to complete and sign the porting document on your behalf.  
  • We will then check and send to the appropriate porting department to process the port.  During this time we will need to set-up and test your new service prior to the porting date. At the designated porting date and time, your number will appear in your Callagenix account running the required service

NGN Porting document

  • If your number is with a reseller and found to be with Energis, Cable & Wireless or Verizon, we may be able to migrate the number to Callagenix. This is a much simpler process and only requires your written authorisation.

Migration document


There are no costs from Callagenix to port your number.

To port your number to us please call us on +44 (0) 333 247 0000