Savvy travel bookers who click on low price adverts may find they are often lead to air, rail and bus websites which do not have any seats at the advertised reduced fares.The advertising watchdog has found that in at least one case this is because there were never many low fare seats available at all, and has banned Megabus from advertising its seats as “from £1” after it was found only three per cent of seats were available at that price.The company uses distinctive blue and yellow buses, emblazoned with the advertisement: “From £1 + 50p booking fee (subject to availability)”However, the ASA has instructed the company not to use this tagline unless a significant number of seats were being sold at that price.Two complainants flagged the misleading advertisement to the ASA, after Megabus sold its journeys from Aberystwyth to Birmingham as “from £1”, as well as its travel from Leeds to new destinations in Yorkshire and offered “day trips from £1” from London to Bath. The company assured potential customers that “as always, our fares are from £1”. Megabus revealed that one each route there was just one £1 ticket available at the time the adverts were viewed. The company explained the number of fares available for £1 for any given route varied due to the amount of stops and number of bookings.For the Aberystwyth to Birmingham route, there were theoretically six tickets available out of 147, and for London to Bath there were three out of 96 on the five-stop route, of which one was for the full journey from London to Bath. There were no £1 fares at all for the route from Leeds to various destinations in Yorkshire, because there was an additional fee for the second leg of the journey.Those hoping to secure a £1 ticket, the company explained, have to book around a month in advance.The ASA ruled: “We considered that customers would be able to understand that not all tickets would be priced at £1, but would expect to be able to find the ‘from’ price in the ads for tickets across a range of dates if they booked in advance.”Because only between three and four per cent of fares available were priced at £1, the ads must not appear in their current form and that in future Megabus must “ensure in future that when using the ‘from £1’ price claims, a significant proportion of the advertised fares were available at £1, so consumers would have a reasonable chance of obtaining the products at the advertised ‘from’ price”. The ASA ruled that the company can only market its seats as “from £1” if a significant amount of seats are at that priceCredit:PA Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.