Hat tip to this Flyertalk thread, it’s possible to purchase tickets between several cities in the UK and several cities in the US — in business class — for under $100 roundtrip.

You have to originate in Europe. This works from London, but not exclusively so.

This was first discovered on United, but it appears to work for most carriers. Here’s some of the airlines that the ITA Matrix will price an itinerary like this in business class — in Danish Kroner (so you’ll want to use a credit card with no foreign currency fees when purchasing).

And here’s ITA Matrix pricing first class, it even prices for Swiss and Lufthansa first class.

The question is, where to book. It was initially suggested to use United.com, and indeed you can get the price to come up there, but with a US billing address for your credit card the site may not be willing to let you purchase what it prices in Danish Kroner. And Expedia.dk doesn’t seem to price itineraries this way.

You may need to experiment with booking sites to find one that will allow you to price this way in Danish Kroner and let you purchase with a US credit card.

Let’s walk through pricing at United.com: the way you buy in Danish Kroner is just to walk through a purchase and then when you reach the ‘Complete Purchase’ stage after you’ve selected an itinerary, you have the option to change your billing country.

Change your billing country to Denmark and the website will price in Danish Kroners (DKK).

You may need to pick your flights again, but pricing will be very favorable — sale pricing will be revealed, instead of $11,000 or more you may see prices of just over 500 DKK or US$80.

Indeed, I was able to select an itinerary in business class between Newcastle, UK and San Francisco for 559 DKK all-in (US$85).

But as I say, a US credit card forces you back to US dollars and a higher price. Your credit card may or may not allow the purchase to go through leaving billing country as Denmark.

Suggestions?

Update: One Flyertalk member using United.com says,

on the last page after entering my us address and zip I left the country as Denmark.No problem at all

Another says,

use paypal as payment method and then you can pay with paypal with a danish billing adress with no issue whatsoever

Update 7:23am Eastern: This works from the UK to other parts of the world, too — here’s first class London – Sydney roundtrip.

And here’s first class London – Johannesburg roundtrip.

Update 7:32am Eastern: Remember that American AAdvantage will give you 3000 – 12,000 bonus miles per segment for long haul international first class and many business class fares on American or US Airways flights or on codeshares operated by British Airways, Iberia, Finnair, Japan Airlines and Qantas.

Update 7:37am Eastern: A Flyertalk member points out,

you can do stopovers in US on the way to south america 2 trips 1 ticket.

[Honolulu] is a valid stopover point to South america by the way

Update 9:13am Eastern: Confirmed this is still alive.

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