Judging by the number of hits on this blog piece we’re not the only ones who find number porting a nightmare – Mark T, March 2013

Bit of a specialist moan this week about telephone number porting so please feel free to ignore unless you are in the business in which case I would be very glad of your input.

We provide VoIP telephone systems to our clients – both hosted, i.e. the VoIP PBX is up in the cloud, – and also on-premise VoIP PBX’s. Very often our clients have existing phone numbers they want brought into the new VoIP system. This is where the fun begins.

Unlike moving an internet domain from one provider to another, which, mainly, goes quite well and is well understood, the process for moving phone numbers from one provider to another is opaque, bureaucratic, long winded, error prone, costly, and little understood.

We have won a new contract this month for our VoIP and I.T. systems and support and as part of this process we are porting in 10 existing phone numbers. I have already been ‘fined’ once by OUR ITSP for putting through a porting form that was rejected. The numbers are now starting to trickle to us but we are not informed when they actually come to us.

Part of the problem with telephone number porting is that the phone number never really leaves the company that first registered the number. They remain the so called ‘range holder’ as far as I can tell. When porting a number from provider to provider it doesn’t matter what your current telephone provider tells you about their procedures, account information, etc., as it is still the original ‘range holder’ that the porting request ultimately ends up with. Here lies one of the major problems with the process; how are you supposed to know who the original range holder is? Our provider is useless at passing on this kind of information – they seem to think that telepathy actually works. I have now found a couple of tools that identify the range holder for a given (UK at least) number.

If anyone can point me in the direction of good quality information about the rules regarding number porting in the UK i would be a happy man. It seems to be a bit of a closed shop and the processes, and consumers rights, are not well publicised. I get the feeling that the big incumbent players in telephony like it that way as more agile, responsive players such as ourselves are eating their lunch.

Comments very welcome.

UPDATE 13/09/12

This URL provides a lot of detail about your phone number and potentially the range holder for the number;


UPDATE 23/01/13

Seamus left this very helpful comment with some more information and links, which is much appreciated;

A number’s Rangeholder can be found out using:


Or you could use:


The first one is used by many industry members.

The same information can be gotten from the OFCOM site – if you don’t mind trawling through Excel sheets that is.

If the Rangeholder is no longer the Carrier/Operator/Communications Provider then they don’t decide whether the port succeeds or not and (should) simply update their records so that calls continue to route correctly, etc.

The problems tend to start when the Rangeholder, actual current Network Operator and the service provider (seller of the service to the end user) are all different.

The service provider (end-seller) should be able to say in an instant who all three of the above are.

Without this info a port request is a real shot in the dark!

The remaining info that must be confirmed are the post-code the Network Operator has on file for the number(s), number of lines provided and associated numbers on the account. These six details being correct will ensure a successful port or will at least mean the rejection details provided will indicate how to submit the next request correctly.

Best of Luck!

by hostadmin on Aug 29, 2012 at 10:52 PM

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