The 01633
telephone area code
A telephone numbering plan is a type of numbering scheme used in telecommunication to assign telephone numbers to subscriber telephones or other telephony endpoints. Telephone numbers are the addresses of participants in a telephone network, rea ...
covers the city of
Newport and surrounding areas in the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...
. Before
PhONEday
PhONEday was a change to the telephone dialling plan in the United Kingdom on 16 April 1995. It changed geographic area codes and some telephone numbers. In most areas, a "1" was added to the dialling code after the initial zero. In Bristol, Le ...
the area code was 0633, which was originally dialled as "0NE3" where the "NE" were formed from the first two letters of NEwport on the telephone dial. In common with all other British area codes the initial '0' is a
trunk prefix
A trunk prefix is a digit sequence to be dialed before a telephone number to initiate a telephone call for the purpose of selecting an appropriate telecommunications circuit by which the call is to be routed.
Making a domestic (national) telephone ...
that is dropped when dialling from abroad.
Coverage
The 14 exchanges listed in the table below form the 01633 code area as of 2012:
History
The
Group switching centre
A group switching centre (GSC) was a United Kingdom telephone exchange used to provide local and trunk routing to local exchanges within its own and if required, adjacent group areas.
Group switching centres formed a component of the trunk mechani ...
(GSC) for the Newport charge group was the Savoy exchange. This exchange alongside the Chartist, Maindee and Maesglas exchanges formed the Newport
linked numbering scheme
A linked numbering scheme (LNS) is a dialing procedure in effect in a service area within which call routing between adjacent exchanges does not require a dialing code. The term is only used in the United Kingdom, but not in the North American ...
whereby local numbers could be dialled directly and with the
STD code
Subscriber trunk dialling (STD), also known as subscriber toll dialing, is a telephone numbering plan feature and telecommunications technology for the dialling of trunk calls by telephone subscribers without the assistance from switchboard oper ...
0633. The surrounding dependent exchanges could be accessed via local codes and longer STD codes based on 0633.
Dependent exchanges
Smaller exchanges around the GSC were parented onto it. From them the digit 9 was dialled to access the GSC. The codes from the GSC to the dependent exchanges are listed in the table below:
To dial from one dependent exchange to another one first dialled 9 to access the GSC then dialled the local code to the destination exchange. Thus a caller from Machen to Magor would dial 947 before the subscriber's number and a caller from Risca to Cwmbran would dial 93. A caller to a Newport number in the linked numbering scheme would simply dial 9.
Changes
Over time the local codes were abolished and the dependent exchanges became part of the linked numbering scheme. This meant the 3, 4 and 5-digit numbers became 6-digit numbers by means of a prefix that was unique in the 0633 code area.
*By 1983 Llanwern 4-digit numbers (2000–3999) were prefixed with 41.
*Caerleon 4-digit numbers were prefixed by 42. All were 6-digit by 1976.
*Rhiwderin 4-digit numbers were prefixed by 89.
*Risca 3-digit numbers were prefixed by 600 and 4-digit numbers prefixed by 61. All were 6-digit by 1974.
*Penhow 3-digit numbers were prefixed with 400. All were 6-digit by 1983.
*Machen 3-digit numbers were prefixed with 440. All were 6-digit by 1983.
*Magor 3-digit numbers were prefixed with 880. All were 6-digit by 1983.
*Castleton 3-digit numbers were prefixed with 680. All were 6-digit by 1979.
*Tredunnock 3-digit numbers were prefixed with 450.
*Cwmbran 4-digit numbers (2000–5999) were prefixed with 48 and 5-digit numbers (60000–79999) were prefixed with 8.
The remaining 5-digit numbers in the Newport area (50000–59999 and 62000–69999) were prefixed with 2 in 1990. Since then all numbers have been 6-digit and the previous prefixes have been reused by other communications providers.
References
{{Coord, 51.5937, N, 2.9987, W, display=title
1633
Newport, Wales