Telephone numbers are an integral part of life. “Can I get your number?” remains one of the most hopeful and fraught phrases in the English language.

However, the numbers we enter into our phones are a “lie”. The technology that created telephone numbers is more than a century old and has largely been phased out of both our daily lives and the telephone networks themselves. Furthermore, we are in a world where the way we contact people has changed beyond all recognition. In the world of ‘click-to-call’, the days of telephone numbers are, well, numbered.

The origins of the telephone number lie in the mechanical origins of the earliest telephone exchanges. They were literally hard wired into the system. The original switchboards involved human operators moving jack leads by hand. However, this process was quickly automated – the first fully automated telephone exchange in the UK was opened in Epsom in 1912. The number called would cause physical machinery to route the call through a succession of mechanical switches, the position of the switches being determined by the number.

Going mobile changed the rules for telephone numbers

However, this physical connection between numbers has, in almost all cases, vanished. Numbers such as national/non-geographic numbers and toll-free numbers sat outside the initial numbering framework. The advent of mobile telephony was also a significant change for two reasons.

The first reason is that mobile numbers are linked to SIMs rather than a traditional local telephone exchange. The connection between the phone/SIM and the number is indicative rather than physical: if you move the SIM to a new phone the number follows.

The rise of the mobile phone was also the catalyst for the expectation of number porting – i.e., taking your number with you when you switch networks. Number porting spread to fixed-line numbers and further weakened any connection between location and the number.

Names not telephone numbers

Mobile phones also changed our behaviour in another way. The rise of contact lists in phones meant that when we called someone we selected their name rather than dialling a number.

In this sense, telephone numbers have become more like web addresses. When you go to a website and type in a “www” web address, that address is a mask for a more complicated IP address. A Domain Name Server (DNS) translates that address and through a hidden directory systems routes you to the website. Telephony is moving in the same direction.

Click to call

The advent of IP telephoning means that many calls are now made over data connections rather than the public service telephone network (PSTN). Common examples of this are calls made using WhatsApp or Messenger.

Collaboration platforms such as Teams, Webex, and Zoom also use IP Telephony when calling another user of the same platform. This ‘click-to-call’ functionality removes the need for a traditional telephone number.

Systems such as Microsoft Teams need to use gateways to connect to ‘normal’ numbers, but they point to a world without telephone numbers.

Indeed, often when we think we are calling a number, we are not. When your Uber driver or Airbnb contact sends you a number that number is, like a web address, a mask. Companies such as Uber operate systems that mask drivers’ real numbers whilst still providing a contact mechanism for the customer, and the same applies when the driver calls you.

The systems at present rely on the PSTN network, but there is no reason in the future that these platforms will instead utilize an IP telephony system in favor of connecting to the PSTN.

Voice networks in decline

Market data shows that voice calls are less and less common as a means of contact either between friends and family, work colleagues, or customers and businesses. After decades of consistent growth, voice network operators are now reporting a decline in voice call volumes.

Changing habits and new technologies mean that the humble telephone number may one day be history.