Three university friends have today arrived to a homecoming reception back in London following a 15-month long trip around the world in a black cab which has seen them set two world records.

Paul Archer, Johno Ellison and Leigh Purnell arrived in London's Covent Garden this morning in their K-reg black cab (affectionately known as 'Hannah') following a trip that clocked up in excess of 43,208.40 miles on the meter.

The trio - who have raised over £20,000 for charity since beginning the journey in February 2011- travelled across four continents and 50 different countries and run-up an cumulative taxi fare of nearly £80,000 by the time they were back on British soil.

As well as earning the Guinness World records title for Longest journey by taxi, the journey also the group also earned the title for the highest altitude reached by car after the three drove Hannah up to a mountain pass in the Golmud region of Qinghai Province in China, some 5,225.4 metres (17,143 ft) above sea-level.

The incredible ride saw them negotiate herds of Armenian sheep, evade the Taliban in Pakistan, and even get arrested by the Iranian Secret Police where Paul was subsequently deported as a suspected spy.

The final leg of the 'It's On The Meter Expedition' was sponsored by Black cab app, Get Taxi, who plan to donate five per cent of the monster bill to the British Red Cross.

The trip, intended originally as a London to Sydney excursion, saw the lads successfully raise £15,000; £5,000 short of their ultimate goal.

Get Taxi pledged them the remaining money, and also provided the trio with the fuel, accommodation, and state-of-the-art GPS tracking systems used in their own fleet of cabs needed for the crew and Hannah to fully circumnavigate the globe.

"It's been emotional," Paul explained. "We've been utterly overwhelmed by the support we've been given by everyone at home, as well as the countless number of strangers we've encountered who've been kind enough to help us on our way, especially when adversity struck and we thought, at one point, that our trek would be over".

"Apart from some hairy moments where we were arrested in Moscow, arrested by the Secret Police, deported back to the UK and were refused entry to Moldova for losing the appropriate documentation at border control (luckily the President himself gave us a personal pardon!), we've taken away with us some awesome memories. Obviously, we would not have been able to do any of this without Hannah, our beloved and trusty steed!"

The idea to travel the world in a black cab was borne out of the lads' own cab journey home one evening, after a night out on the tiles. "We thought: why not see if we can run up the world's longest, most expensive taxi journey, and do it all for charity?" recalls Johno , 28, Leeds.

Commenting on the expedition, Neil Fullman, CEO, Get Taxi UK said: "The lads have much to be proud of. And we're of course thrilled that we have helped them complete an epic journey that few, if anyone, will ever experience. It's great to have played a significant part in helping them to both realise their goal and achieve record-breaking history."