The Complete Number Porting Handbook

The Number Porting process is led by the GCP (Gaining Communications Provider) at all times

Sipdesk will work tirelessly to ensure that your incoming phone numbers are timely ported to the Sipdesk VoIP service. Nonetheless, we can neither guarantee the successful porting of numbers nor declare a specific timeframe within which the numbers will be ported (this includes but isn’t limited to the least industry standard lead time-frame for the type of import). Additionally, we cannot guarantee that no problems are going to be experienced during the number porting process from your current provider.

It is important for you to note that while number portability in the UK is controlled by Ofcom (the Telecommunications Regulator in the UK) as guided by the EU regulations in place, the geographic and non-geographic number porting process in the UK has no guarantees. Therefore, all the lead times that are mentioned in this brief are essentially the minimum standards set by the industry.

As an accepted practice, Ofcom only assigns numbers to service providers that have satisfactorily completed the technical SE (Service Establishment). In general, a porting contract with at least one of the available networks should also be signed to have the permission for exporting their allocated numbers. But then again, this isn’t a binding requirement for acquiring telephone number allocations from Ofcom.

Bear in mind that there’s no support for Wholesaler or Reseller porting amongst service providers since the portability of numbers is only possible for end users or subscribers who wish to switch from their service provider. This is applicable for any kinds of imports to Sipdesk as well as exports from XiniX World. For more information, refer to the document here.

As a result, any kind of import or export number porting orders received by XiniX World and are suspected to be either wholesaler or reseller ports are going to be rejected. On the other hand, requests of service change (such as ISDN to Hosted PBX) are open to being allowed on a case by case basis.

You must also note that in case the number or numbers undergoing import are found active within the Directory Enquiries (i.e. Directory Management Solutions or the BT Phonebook), you stand to incur some charges without initial notice once a reprint is done. To avoid any unexpected costs, you should cancel any unwanted directory services with your current service provider as soon as possible.

The process of number porting could also lead to extra charges levied by intermediate third parties (such as your current and new service provider) which are directly responsible for the facilitation of your porting order. Therefore, you have to be aware of such charges before you fully commit yourself to a porting order. Furthermore, you should also be aware of the fact that revising the date of porting may not be possible as that will either depend on the number due for porting or the type of circuit.

Once a number is officially ported from a fixed phone line, the initial line is automatically taken out of service. As a result, any and all extra services such as voicemail and broadband that were offered directly on to that phoneline are also cut off. The prefixing of number ports on both digital line (ISDN) and analogue activation of imports from BT (as the RH) typically takes place at the exchange level.
After a phone number is ported to us, the initial RH changes the number’s prefix so that it is routed out to IP Exchange. It is transferred to the IP Exchange platform then reprogrammed into their main phone routing engine, after which all the number’s incoming calls from then onwards are routed to the Sipdesk platform.

Once a number is officially ported from a fixed phone line, the initial line is automatically taken out of service. As a result, any and all extra services such as voicemail and broadband that were offered directly on to that phoneline are also cut off. The prefixing of number ports on both digital line (ISDN) and analogue activation of imports from BT (as the RH) typically takes place at the exchange level.

After a phone number is ported to us, the initial RH changes the number’s prefix so that it is routed out to IP Exchange. It is transferred to the IP Exchange platform then reprogrammed into their main phone routing engine, after which all the number’s incoming calls from then onwards are routed to the Sipdesk platform.

For us to port your phone number through the Sipdesk VoIP platform, all the numbers are required to have the following.
1. The proof of your ownership of that telephone number, preferably a copy of your most recent bill from your CNO
2. Proper consent from you (the subscriber) for porting the number, ideally in form of a signed GNP Customer Letter of Authority
3. Appropriate details of the phone number in form of porting documents completely filled as required
4. CUPID of the RH. You can find it by logging on to www.telecom-tariffs.co.uk , which you should counter-check against the S1 allocation form from Ofcom
5. The LCP CUPID of the company that charges you for that phone number, which may also be a RH.

Note: without the above information, we are not able to carry on with any number porting procedure.

There are several factors that can lead to the delay of porting orders, they include:

• Presence of a security tag or Redcare on the line In this case, you either have to transfer the service to another circuit number or cancel the Redcare before porting of the phone number can proceed.
• An incorrect postcode or address of installation or some of the information is not matching what is of file at the current network operator.
• No response from the RH/LCP. You must always alert your CNO of your porting intention to prevent any hold up of your port.
• Lack of a Service Establishment with the RH/LCP. In this case, there’s nothing you can do as a subscriber to rectify this.
• Improper labelling; for instance a multiline as a single line. You must always verify the type of line with the RH/LCP.
• Inaccurate telephone information such as the DDI range or main billing number. Ensure that you verify the details of all attached telephone numbers with the LCP/RH.

The process of porting telephone numbers is usually led by the Gaining Communications Provider(GCP) and is exclusively available for the subscriber/end-user. This therefore means that for subscribers/end-user to successfully export numbers from us, they ought to follow the same number porting process but with another provider. Basically, the data submitted by the LCP is validated as needed. In addition, a CLoA (Customer Letter of Authority) checked before the progressing of any export is also a requirement with the new service provider. The guidelines of porting follow a standard procedure across the industry and so, the porting process will just be the same with any other service provider.

For efficiency and faster processing of your export request, ensure that you provide Sipdesk a CLoA copy particularly if you have a short porting timeframe. Otherwise, delays in the reception of this form from the GCP leads to a time-out in the porting process since it cannot be authenticated.

Naturally, in cases where we are not the RH, any telephone number ported into the BT IPEX can still be ported out again. Telephone numbers that were imported to Sipdesk can generally be exported through the same means with which they were imported at first or accordingly split. On the other hand, if a range of phone numbers was initially imported, then that entire range of telephone numbers has to be exported so as to maintain the number(s) that are desired.

For geographic numbers where Sipdesk is the RH, they can be exported away from us but it comes with a few precautions to the IP Exchange platform. With any luck, these should however be annulled in the imminent feature. The points that you should be aware of include;

• After the number ranges that were assigned by Ofcom to RHs founded on IP Exchange are exported away from IP Exchange, they cannot be taken back to IP Exchange yet. It is important to note that this also comprises of any other IP Exchange CP. For instance; a phone number transferred to BT PSTN cannot currently be ported elsewhere.
• Currently, ranges of numbers assigned to us by Ofcom which are founded on IPEX can be prefixed away from IP Exchange only once. Therefore, this is to mean that changing or updating of porting prefixes of subsequent exports to other CPs is presently not possible. Consequently, any previous transfer of the Sipdesk phone number is permanent until further instruction by IP Exchange as indicated above.
• Ranges of non-geographic numbers (starting with 03, 05, 08 or 09) assigned to Sipdesk by Ofcom and founded on IP Exchange cannot be transferred at the moment. As a result, such export requests are out of our technical scope for now.

We also cannot export numbers that are out of service. Any numbers that are to be ported ought to be live and working. Porting requests for numbers that fail after a phone call attempt are rejected automatically.

We do not support Bulk end-user/subscriber number porting by Wholesalers/Resellers into or out of Sipdesk. This is because the porting of phone numbers is only available for end-users/subscribers who only wish to switch their subscriber. Thus, any kind of reseller/wholesaler porting requests are effectively denied. The above procedure is compulsory under all conditions. For more information, please refer to this document here.

Definition of Types of Telephone Lines;

• Simple DDI – This refers to several digital lines (SS7/E1/T1/ISDN) on a single or several phone numbers, containing a primary billing number. It may consist of a SNDDIs on the circuit and/or have an entire block of DDI’s (at least 10, in multiples of 10)
• Complex DDI – Several digital lines (SS7/E1/T1/ISDN) that consist of a portion of a block of DDI’s and a primary billing number. It’s also quite important to keep in mind that all DDI’s that are connected to the circuit also have to be recorded on the porting document. Clear instructions should also be given indicating which numbers are to be ported and consequently, any un-ported numbers are given back to the Range Holder.
• International – These are telephone numbers that come from countries that are outside the United Kingdom
• Multi Line Geographic – Refers to several lines on a single or several phone numbers, together with single-number ISDN and WRL analogue Multi-Line.
• Single Line Geographic – This is a single phone number that starts with 01 or 02 and is neither the primary billing number of a DDI range nor part of a DDI range. Likewise, it also doesn’t form part of a multiline.
• Single Line Non-Geographic – One non-geographic phone number that isn’t part of a Feature Line or Multi-line. Additionally, it is neither the primary billing number for a DDI range nor is it part of a DDI range.

• Multi Line Geographic - Copy of Latest Bill, Letter of Authority, Porting Form
• Multi Line Non-Geographic - Copy of Latest Bill, Porting of Non-Geographic Numbers Notice
• Non-Geographic - Copy of Latest Bill, Porting of Non-Geographic Numbers Notice
• Simple & Complex DDI - Copy of Latest Bill, Letter of Authority, Porting Form
• Single Line Geographic - Copy of Latest Bill, Letter of Authority, Porting Form

• Complex DDI - 22 to 25 business days
• Multi Line Geographic Import - 7 to 25 business days
• Non-Geographic Import - 15+ business days
• Simple DDI - 10 to 23 business days
• Single Line Geographic Import - 4 to 13 business days

1. You, the customer (subscriber/end-user) start by submitting your request to Sipdesk which involves submission of a copy of your most recent bill, a CLoA (Customer Letter of Authority) and a porting form.
2. Through an online portal, Sipdesk will the submit the details to IPEX together with a CRD (Customer Required Date)
3. IPEX carries out a look up on their database automatically to verify the RH and type of line.
4. The order is confirmed after it is verified that the information matches with the RH/LCP records.
5. RH/LCP sends a notification to IPEX confirming that the request has been received and records the time and date of acceptance.
6. Sipdesk then sends a notice to you, the customer that the number porting request has been accepted.
7. In a minimum of 24 hours before the porting occurs, Sipdesk Word adds the porting telephone number to the account of the customer in readiness for receiving traffic from BT IPEX
8. During the date and time of porting, IPEX loads the phone number automatically to the ENUM and forwards phone calls from that phone number to Sipdesk so that they are set to receive traffic from the Range Holders.
9. Porting prefix is automatically applied by the RH so that the phone calls are routed to IPEX
10. IPEX sends us a confirmation that the phone number has been ported successfully.
11. Sipdesk carries out a test-call after reception of the successful porting confirmation message to ensure proper routing of calls. In case there’s a problem, the issue is immediately escalated to BT.

1. The customer (subscriber/end-user) begins by submitting a request to Sipdesk which involves submission of a copy of the most recent bill, a CLoA (Customer Letter of Authority) and a porting form.
2. Through an online portal, Sipdesk will the submit the details to IPEX
3. This information is then manually filled on a NPOR form by IPEX
4. The NPOR form is forwarded to BT Openreach, after which BT Open reach sends it to the RH/LCP.
5. Information on the NPOR is verified by RH/LCR and a response is accordingly sent back to BT Openreach together with appropriate reasons in case of a rejection.
6. The response is then sent to IPEX by BT Openreach
7. If the porting request was accepted, the assenting response if forwarded to Sipdesk authorizing the time and date of commencement of the process of porting.
8. In a minimum of 24 hours before the porting, Sipdesk adds the numbers into the account of the customer in readiness for reception of traffic.
9. On the day and time of porting, we carry out a manual configuration of the number porting on the IPEX portal following the start of the Port Configuration Window. This automatically loads the number onto the ENUM.
10. In addition, during the confirmed date and time of porting, Sipdesk Word contacts IPEX giving the MBN and/or reference number(s) then requests for the porting procedure to progress. We also make a test phone call to ensure a correct ENUM load.
11. After that, Openreach proceeds with the porting, in which the Range Holder assigns the porting prefix and incoming traffic on PSTN is routed to Sipdesk if everything is as required.
12. In case of a down-time of more than 15 minutes, Sipdesk Word contacts IPEX with a request of escalating as a result of the down-time.

1. The customer (subscriber/end-user) starts by filling in a separate porting notice of a Non-Geographic number. This form has to be typed carefully, printed on a subscriber-headed paper, dated and signed. It should then be sent back to Sipdesk together with a copy of the most recent LCP bill. Where available, there should be an account number the customer has with the LCP as well as the physical address, email address and phone number of the LCP. The GCP on the other hand ought to be Sipdesk plus our address indicated appropriately.
2. In the event that the transaction involves resellers, the lead time of porting will increase. As such, all the parties involved must be notified of the porting request. The shortest lead time possible for number porting of a non-geographic line is 15 business days.
3. After all the appropriately filled paperwork from the subscriber is received, Sipdesk will send the paperwork to IP Exchange for processing the porting request on our behalf through the Inbound Services of BT. BT’s Inbound Services then send a number porting request to the CNO (which may also be a reseller) or accordingly deny the porting request due to the porting inability or even improper paperwork.
4. Once the porting request to the customer’s provider is approved, BT approaches the RH with a porting order.
5. After accepting of the porting order an agreed upon date for the execution of porting is confirmed to the IP Exchange and if necessary, a time range or even a fixed tome is chosen.
6. In a minimum of 24 hours before the porting, Sipdesk will include the required number(s) to the end-user’s Sipdesk Word account in readiness of receiving the incoming calls.
7. On the day and time of porting, IPEX builds the numbers (s) upon the ENUM, and after that it contacts the Range Holder to commence the porting prefix.
8. Sipdesk carries out test-callz after reception of the successful porting confirmation message to ensure proper routing of the numbers. In case of a down-time of more than 15 minutes, Sipdesk Word contacts IPEX with a request of escalating as a result of the down-time.

Glossary of Terms
The abbreviations used in the context of this document, are as highlighted below:

• CNO = Current Network Operator
• CP = Communications Provider
• CRD = Customer Required Date
• CUPID = Communications Unique Provider ID
• DDI = Direct Dial In
• ENUM = E.164 Number Mapping - the call routing engine from IPEX which is responsible for directing inbound calls on phone numbers to the assigned destinations or carriers
• GNP = Geographic Number Porting
• BT IPEX = British Telecom IP Exchange
• IPEX = IP Exchange
• ISDN = Integrated Services Digital Network (, ISDN30e or PRI, ISDN2e or BRI)
• LCP = Losing Communications Provider
• NGN = Non-Geographic Number
• PSTN = Public Switched Telephone Network
• RH = Range holder
• SE = Service Establishment
• SS7 = Switched Signalling 7 – a set of protocols usually on a fixed E1 circuit that define the routing and signalling of calls

Sipdesk has fruitfully done an import of numbers from the RHs listed in the table below:

– Any Annex A CP form BT IPEX (Annex B Communications Providers [i.e. Gamma] charge similar rates on both IPX and TDM and can’t be ported with no direct porting contract between us and the Communications Provider)
Note: In case the RH of a phone number(s) that you are looking to port away from isn’t mentioned on the above table, feel free to contact our porting support team to get more information on whether it is possible to proceed with a porting request for your desired number(s).