Richard Elloway said he was treating the trip as a race
A retired head teacher using his free bus pass to go from Land's End to John O'Groats and back again says the trip is the "ultimate holiday on a pension".
Richard Elloway, 61, hopes to become the first person to make the return journey since the extension of free bus travel for over-60s in England.
Scotland already offered a free travel scheme for the same age group.
Mr Elloway, from Somerset, is now travelling back down the western side of the country using local buses.
He took with him bus timetables, a toothbrush and clothes.
He said: "I am treating it as a race, but I appear to be the only one taking part.
"It took me one week and six hours to get to John O'Groats and I am already travelling at a good rate back."
Mr Elloway said "all but two" of the hostels he stayed at refunded him after he told managers of his intention to use his journey to raise money for Breaks4Kids, a charity of the Youth Hostel Association providing holidays for disadvantaged children.
He said Britain's public transport network had been a "bit hit and miss," and so far he has only spent £40.
"Who says you can't get away on a pension?" he added.
OAPs are allowed to travel anywhere in Scotland for free under the national bus pass scheme, but it is understood Mr Elloway got special permission to carry out his round Britain trip.