The four numbers that make up Liverpool's dialling code are used by many of us every day - and date back quite some time.
1958 saw the introduction of subscriber trunk dialling codes, allowing people to make non local calls without the need of operator assistance. Before then, people had to ask the operator for assistance so they could be put through to another town or city.
The development made by dialling codes was publicised by the Queen, who phoned Edinburgh from Bristol - at the time this was longest distance call which could be made in the UK. This was during the era when the old General Post Office controlled and ran telephone services in the UK.
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Liverpool 's dialling code became 051 , with the number 5 representing the first letter of the city (L) on the rotary telephone. Manchester's code was 061, with the number 6 representing M for Manchester. Birmingham was 021, with the number 2 representing B. Liverpool's STD code inspired the name of city centre nightclub the 051, based on Mount Pleasant, which was one of the city's most popular clubs in the early 90s.
British Telecom, now known as BT, was formed in 1980, and assumed control of the UK's telephone network. In 1982 , in a significant step, the then Conservative government broke the state's monopoly on the telecommunications industry.
In 1984 the government offered half the shares in BT to the public, during a privatisation which was a flagship policy of the Thatcher government. In 1991 British Telecom changed it's trading name to BT.
The next significant milestone for the city's dialling code was on April 16 1995, an event known as PhONEday. This was the event that added the digit 1 to Liverpool 's dialling code, making it 0151.
BT spent two years preparing for the transition and spent £16m on a media campaign advertising in newspapers and on television to make sure the public understood what would happen. The much publicised event took place on a Bank Holiday weekend, when telephone traffic was much reduced. The decision to add a 1 to all national codes created an extra 10 billion phone lines for an expanding and burgeoning telecommunications industry.
The UK's international access code also changed from 010 to 00, allowing Britain to follow access codes in the European Union. Today BT is a global player in telecommunications, offering a range of technology to households and companies. BT is also now a leading broadcaster of sport, showing Premier League football.
BT still has a statutory obligation to maintain a network of phone boxes in the UK. The original red phone box was designed in 1924 by architect Sir Giles Gilbert Scott, who also created Liverpool's Anglican cathedral.
There used to be nearly 80,000 red phone boxes in the UK but that figure has now reduced to around 10,000.
