Table top views: Cape Town / Getty

You can reduce the fare by building in a 24-hour stopover

Q. I am a lone passenger holding dual nationality and I'm looking for a one-way flight to Cape Town from a London airport. Travel agents are not forthcoming with regard to all the options available – which is almost the same cost as a return flight. I am not necessarily seeking a direct, non-stop flight, as cost is my main concern. In addition, I do not have the usual constraints associated with long haul and can travel at short notice from late June. Michael Black

A. I tested a range of airlines, with Saturday 27 June as a departure date and looking with or without a return trip 10 days later. The lowest return was £570 on KLM from Heathrow via Amsterdam, with Turkish Airlines from Gatwick via Istanbul next at £650. Both are excellent fares for a round-trip journey of about 12,000 miles.

Looking at the one-way fare alone, though, everything goes topsy-turvy. The KLM fare increased to £650 – so you would be better off buying a return and throwing away the inbound half. In contrast, Turkish Airlines has competitive one-ways. It offers a fare of £468 from Gatwick on, seemingly, any day you like (or £30 more from Heathrow). However, you can reduce the fare to £416 by building in a 24-hour stopover in Istanbul – this reduces your Air Passenger Duty liability, and the £52 saving will pay for a hotel and meals.

An even smarter idea could be to change your destination to Johannesburg, which has more competition and therefore cheaper flights. Ethiopian Airlines' flights from Heathrow via Addis Ababa pop up at £351, and you can find onward flights on the low-cost airlines Mango or Kulula for £30-£40 one way. You might not want to do this because of the hassle (and extra charges) if you have a lot of luggage, but at least you have the choice.