Address Matching
Dialogue service to confirm an end users address details


Asymmetric Digital Subscriber Line – a form of DSL, an ‘always on’ data communications technology that enables faster data transmission over copper telephone lines than a conventional dial up modem can provide. ADSL offers faster download speeds than upload speeds.

Advanced Intelligent Network – a telephone network architecture that adds advanced computer intelligence to the telephone system such as voice recognition.

Anonymous Call Rejection
Anonymous Call Rejection (ACR) is a network based service that allows End Users to block calls from people who have withheld their numbers.

Dialogue service to confirm and book appointments


Business to Business

Billing Account Number – the main telephone number used for billing regardless of the number of lines associated with that number.

Bar 141
Prevents the use of the “141” Withhold Number prefix on a per call basis

Bar 1470
Disables the 1470 facility so that an end user’s Withhold Number service cannot be overridden

Bar 1471
Allows end user’s to recent the use of the 1471/Call Return service

Backhaul Extension Services High speed point-to-point data circuits provided by BT Wholesale for the backhaul of data from BT exchange sites by LLU operators.

Block Terminal
A small terminal box that is used to connect a Redcare compatible alarm to a phone line.

Used to describe a high-capacity, two-way data link between an end user and the access network

BT Retail
The sales division of BT Group, selling BT Group’s voice and data services to individuals and businesses

BT’s 21st Century Network – 21CN is BT’s global, software driven customer network that introduces a new, simpler portfolio of next generation services.

BT Retail

BT Wholesale

Bundled Orders
Where a CP requires multiple single lines to be installed at the same address they may, using the Provide Order, bundle together those multiple orders to enable all lines to be delivered at the same time.

Bypass Number
A second number that is associated with a line that allows a specific feature on that line to be overridden by incoming callers to the bypass number


C and NF
Calling and Network Features

Call Mapping
The Call Mapping service allows CPs to connect to a third party messaging platform to enable them to offer a similar service to Call Minder on WLR3 lines.

Call Minder
A network-based messaging service

Call Return
Allows the end user, by dialling 1471, to hear the number of the last caller together with the time and date of the call.

Call Sign
Users are provided with a second number to their existing Telephone Number. When the call sign number is dialled, the telephone connected to the line will ring with a different cadence to the normal ring tone.

Call Waiting
With Call Waiting, a gentle beep during a call alerts the End User that another call is coming in.

Caller Display
Allows an End User (where they have a telephone with a visual display) to view a caller’s number when the call is being received.

Caller Re-direct
When an End User ceases service and takes up service elsewhere, or has a line renumbered, Caller Redirect can be used to refer callers to the new number, where the End User requests this.

Cancel Other
Enables a CP to cancel a line transfer request, where they are the losing party, where a case of misselling has been identified.

Care Levels
Openreach offer three different levels of service when it comes to assurance, Levels 1,2 & 3, available on Basic and Premium Single Lines and Multi Lines.

Customer Controlled Call Barring

Customer Controlled Call Diversion

Call Data Records

Choose To Refuse
Enables an End User to bar the telephone number of the last answered, incoming call. A maximum of ten numbers can be barred at any one time.

Caller Line Identification – a telephone service that transmits a caller’s number to the called party’s telephone equipment before the call is answered.

Caller Line Identifier Presentation – the ability to call out from a line and present a different number.

Ceased Number Intercept. Another name for Caller Re-direct

Change Of Address

Communications Provider – the term encompasses public and private companies in the fixed line, wireless, internet, cable, satellite and managed services businesses.

Called Party Answer

Customer Premise Equipment – any terminal and associated equipment located at a subscriber’s premises and connected with a carrier’s channel.

Carrier PreSelect – the process whereby a telephone subscriber whose telephone line is maintained by one company, can choose to have some of their calls automatically routed across a different telephone company’s network without needing to enter a special code or special equipment.

Caller Re-Direct or Change Request

Customer Relationship Management – a term applied to processes implemented by a company to handle its contact with its customers. CRM software is used to support these processes, storing information on current and prospective customers.

Communications Service Provider – the term encompasses public and private companies in the fixed line, wireless, internet, cable, satellite and managed services businesses.

Communications Provider ID

Customer Controlled Call Barring
Allows End Users to bar certain types of outbound calls, and/or all inbound calls

Customer Controlled Call Diversion
Allows End Users to divert their calls to another number anywhere in the UK as well as to mobile and international numbers.

Customer Wholesale Portal – a group of reports that provide local service providers (LSP’s) with information to facilitate order processing.



Digital Access Carrier System


Digital Access Signalling System


Direct Dial Identifier – a feature offered by telephone companies for use with their customers’ PBX systems, whereby the telephone company allocates a range of numbers all connected to extensions on the customer PBX.

Debt Management

A family of Openreach products which allow CPs to restrict an end user’s service in a manner that assists CPs in recovering outstanding debt.

Dialogue Services 

Collective name for a number of tools that allows CPs to interact with Openreach to gain information and perform certain order fulfilment and assurance activities

Direct Connect

The Direct Connect service will automatically dial a pre-set number when the handset of the connected telephone is lifted.


Digital Main Switching Unit


Distribution Point


Digital Private Network Signalling System – a network protocol used on digital trunk lines for connecting two PABX.


Dual-tone multi-frequency


Dunn & Bradstreet Universal Numbering Scheme. A nine-digit code assigned by D&B to identify unique business’s separate and distinct operations



Exchange Carrier Code – a four character code assigned to local exchange providers when a company buys (or leases) telephone lines.


Equivalence Management Platform

Equivalence Management Platform

Openreach’s strategic platform providing equal access to its products for all CPs


European Telecommunications Standards Institute


End User

EU (End User)

The customer who contracts with the CP for telephone service

Excess Construction Charges

Charges in addition to normal connection charges, where additional infrastructure is provided to give new or extended service at a customer’s site or other requested location.


Fault History 

A CP may request from Openreach a fault history (closed faults only), covering the previous 90 days, in respect of any line they own. The CP does this with a Fault History request.


Federation of Communication Services – is the UK Trade Association for the communications services industry representing businesses delivering products and services to customers by radio, mobile, fixed and IP telephony.


An exchange based product available from BT Retail. Featureline provides the End User with typical small PBX functionality, but without the need for a PBX.



Gain (or Line Gain) refers to the ratio between the signal and the background noise on the phone line


General Packet Radio Service – a packet oriented mobile data service and can be used for services such as Wireless Application Protocol (WAP) access, Short Message Service (SMS), Multimedia Messaging Service (MMS) and for Internet communication services such as email and World Wide Web access.


Global System for Mobile Communications (originally Groupe Spécial Mobile) – the most popular standard for mobile phones in the world. Its ubiquity makes international roaming very common between mobile phone operators, enabling users to use their phones in many parts of the world.



Indirect Access Call barring


Internet Access Provider – a company which primarily offers their customers access to the Internet using dial-up or broadband access.


Indirect Access – permits you to choose an alternative service provider to route your calls using access codes.


Inbound Call Barring


International Direct Dial

Indirect Access

A service which allows an End User to route an outbound call via a different call provider by dialling an access code prior to the call

Indirect Access Call Barring

A network-based feature that rejects any outgoing call attempt by an End User attempting to use an Indirect Access code.


Internet Protocol – a protocol used for communicating data across a packet-switched internetwork. This is an addressing system actively deployed worldwide.


Integrated Services Digital Network – a telephone system network. The key feature of the ISDN is that it integrates speech and data on the same line.


Internet Service Provider – a company which primarily offers their customers access to the Internet using dial-up or broadband access.



Keeping Customers Informed. Updates that a CP will receive in response to any orders that they place which have been accepted by Openreach following order validation.


Indicates that an order has been accepted by the Openreach Fulfilment system and is being processed.


Informs a CP that an order has been committed to by Openreach’s fulfilment systems, which means that the job has been built, the date allocated and any excess construction charges that apply have been calculated


Informs a CP that the order has been completed by Openreach’s fulfilment systems, which means that the order requested by the CP has been actioned and no further tasks remain outstanding


Advises a CP that an order has been rejected due to a fatal error during the fulfilment process.


Advises a CP that an order has been cancelled either at the request of the CP or because a fatal error was detected during the fulfilment of an order after KCI1 (Acknowledgement) has been sent.



Local Area Network – a computer network covering a small geographic area, like a home or office offering much higher data-transfer rates than a Wide Area Network (WAN).


Law Enforcement Agency

Line Box 

A type of termination that is used with analogue lines consisting of a small box with a faceplate that the End User can plug one telephone into.


Local Loop Unbundling

Loop Disconnect

Pulse dialling or loop disconnect dialling, also called Rotary or Decadic dialling in the United Kingdom


Line Plant Availability



Mobile Network Virtual Operator – a mobile service operator without a licensed network that leases wireless capacity from other carriers.


Metal Path Facility or Meter Pulse Facility



Name and Address Database


Network Channel – industry standard code that defines the type of service provided on a circuit.


Nuisance Call Advice


Network Call Performance


Nuisance Call Service


Non Geographic Number – telephone numbers which gives no indication as to the geographical location of the line being called such as numbers starting with 07, 08 or 09.


Next Generation Networking – a broad term to describe some key architectural evolutions in telecommunication and access networks that will be deployed over the next decade. The general idea behind NGN is that one network transports all information and services (voice and data) by encapsulating these into packets.

Non Served Premises (NSP)

Refers to locations which wouldn’t normally be connected to the Openreach network and which are unlikely to have a postal address

Non-CLI Damage Report

Enables CPs to notify Openreach where they have identified damage to part of the network.


Non-Served Premises


Network Termination Equipment


Network Terminating Point


Network Test and Termination Point


Number Translation Service – the service of routing a telephone call with a non-geographic number starting with 07, 08 or 09 to a hidden geographic or mobile number.

Nuisance Call Service

The part of BT that provides advice on dealing with nuisance calls

Number Portability

The process by which numbers are moved between different network operators



Outbound Call Barring


The regulator for the UK communications industries, with responsibilities across television, radio, telecommunications and wireless communications services.


The UK telecommunications regulator that preceded the creation of

Outbound Call Barring

Allows a CP to prevent End Users making outbound calls over the Openreach network, except to emergency service numbers.



Postcode and Address File


Private Automatic Branch Exchange (see PBX).


Private Branch Exchange PBX: Private Branch Exchange – a telephone exchange that serves a particular business or office, as opposed to one that a common carrier or telephone company operates for many businesses or for the general public.


Product Establishment


Presentation Number


Partial Private Circuit: A circuit providing dedicated transmission capacity between an end user’s premise and another CP’s point of handover, using an interface, as defined at G.703 or G.957 or X.21, all as published by the International Telecommunication Union.


Pay Per Use PPU: Pay Per Use – a telephone service feature that incurs a fee each time it is used.

Product Establishment

The process that CPs must go through before they are able to order the WLR3 product


Public Switched Telephone Network – the network of the world’s public circuit-switched telephone networks, in much the same way that the Internet is the network of the world’s public IP based packet-switched networks.



Quality of Service

Quality of Service

Scheme introduced by Ofcom which mandates CPs over a certain size to report performance statistics in a number of areas, the purpose of which is to allow consumers to compare telecoms providers.



Remote Call Forwarding


A service that provides continuous monitoring of a telephone line that links a professionally installed alarm system on a customer’s premises to an Alarm Receiving Centre (ARC).

Remote Call Forwarding

When an End User ceases service and takes up service elsewhere, or has a line renumbered, Remote Call Forward (RCF) can be used to divert calls to an alternative number, where the End User requests this.


A legal entity marketing and selling telecom products to end users


Retailer ID RID: Reseller Identification – every reseller needs to register a unique number with Ofcom.

Route To Credit Control

When applied to a line, this service automatically connects an End User to a CP help desk when the End User attempts to make outgoing calls (including 1471 calls).


Route To Credit Control


Service Establishment

The process by which Openreach takes on and sets up new customers in order to enable them to become a Communications Provider.


Subscriber Identity Module – part of a removable smart card. The SIM card allows users to change phones by removing the SIM card from one mobile phone and inserting it into another.


Session Initiation Protocol – used to provide VoIP channels to subscribers.

Smart Divert

Same service as CCCD but providing the End User remote access so that the divert options can be applied from another line.


Service Management Centre


Significant Market Power

Social Telephony

Generic term for CP products which are designed for a section of the market who make very small use of the phone.


Service Provider Gateway – a provisioning gateway in a telecoms’ network used as part of Wholesale Line Rental



Temporary Call Diversion


Telecom Expense Management – the management of large telecoms estates covering cost reduction, usage patterns, abuse issues and invoice reconciliation.

Temporary Call Diversion

Allows CPs to request that calls be diverted on a faulty line, while the fault is in the process of being repaired. TCD cannot be placed on a line until diagnostic testing has been completed as it would impact on the testing.

Temporary Out Of Service

When a CP applies Temporary Out of Service (TOS) on an End User’s line a ‘soft’ dial tone is used and they can only call 999. All other incoming, outgoing (including via CPS) and emergency calls will be barred irrespective of the method of dialling.

Time Related Charges

Charges raised to cover time spent by Openreach engineers repairing faults, where this work is not covered under the terms of the Openreach service and for providing or rearranging services or equipment where standard Openreach charges are not available.


Temporary Out Of Service


Third Party Integrator


Telephony over Passive Optical Networks


Time Related Charges



Universal Resource Locator – unique location specifying where the identified resource is available and the protocol for retrieving it


A small rural telephone exchange, developed and supported within BT. The first digital exchange in the BT network, serving a maximum of 800 customers.



Validate Import Customer


Voice over IP – a protocol optimised for the transmission of voice calls via the Internet, also referred to as IP telephony, Internet telephony, voice over broadband, broadband telephony and broadband phone. Utilises Quality of Service (QOS) to transmit voice packets at higher priority to avoid disjointed voice calls.


Virtual Private Network – a network in which some of the links between devices are carried by public connections, such as the Internet or PSTN.


Wholesale 1571

A chargeable unbranded messaging service

Withhold Number

End Users can prevent their telephone number being released across the network on a per call or per line basis. The End User’s CP must request a Withhold Number service from Openreach. There is no charge for this service.


Wholesale Line Rental – wholesale line rental services currently offered in the UK by BT Openreach. A service whereby other suppliers can sell BT products and services.



Indirect access pre-fix to route a call over the Openreach network even if CPS is active on the line.


The prefix used by an End User, before dialling a telephone number, to ensure their number is withheld for that call


Prefix used by an End User, before dialling a telephone number, to ensure their number is released for that call.


See Call Return

1471 Extra

When using 1471 Extra the EU can dial the digits ‘1471’ to hear details of up to the last five calls received, together with the time and date (unless withheld or from an exchange where the callers number is not available). After dialling ‘1471’ instructions will be given advising how to use the services.


Key sequence used on a telephone handset to access Call Minder and Wholesale 1571 messaging services



The name given to the Openreach 21st century network programme


3-Way Calling

The service allows End Users to speak to two other people at the same time even if one of them is abroad. The customer can include or exclude either party at any time during the call.

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