There are situations where you need to make that dire phone call at the airport. This is how to go about it when in Heathrow airport London.
Payphones are common place in london, however most of them are tourist attractions. However at the airport, these payphones actually work.
They operate by inserting a coin into the phone. The amount you put in determines the duration of your talk.
The payphones are important as they can make a call to any part of the UK. Therefore you could call your driver or have someone pick you up.
They charge as low as £1
You could also buy a sim card that you can then insert in your phone and make the call.
Most SIM cards range between £8 to £10 depending on the service provider. You will also be asked to purchase a data plan so as to activate them and make the call.
In case you are in London for a while, this is the best option that you could use.