Let me clear up one of the most common types of questions I get from beginners.

There is no transitive property of miles.

Just because Airline A partners with Airline B and Airline B partners with Airline C does NOT mean Airlines A and C are partners.

Screen Shot 2014-08-03 at 11.51.54 AMFor instance, in yesterday’s post Fully Flat Business Class to Europe for 25,000 Miles, I wrote:

I searched award space on Aer Lingus’ routes from Chicago, Boston, and New York to Dublin for one passenger next April through July.

I searched on united.com. Any space seen here is bookable with United or British Airways miles.

Often when I write such things I’ll get a comment or an email like, “I have American Airlines miles, which is a partner of British Airways. Can I use those miles to book Aer Lingus flights as a British Airways award?”

  • Well, can you?
  • What about using a partner’s more favorable fuel surcharge rules?
  • Can you use American Airlines and US Airways miles to book all the partners of either airline?

The answer is no.

  • American Airlines partners with British Airways (as part of the oneworld alliance)
  • British Airways partners with Aer Lingus (as part of a one-off partnership)


  • American Airlines does NOT partner with Aer Lingus, and American Airlines miles cannot be used to fly Aer Lingus.

Here’s a recent comment from Fen in the same vein:

“When you say that Singapore awards do not collect fuel surcharges on any United flights, do you mean only flights operated by United, or United award flights, operated also by other carriers like Lufthansa? I am asking because United saver awards to Europe are almost always with Lufthansa and I am wondering if we still can use Singapore miles to book those award tickets and not pay fuel surcharges.”

On awards, Singapore doesn’t collect fuel surcharges on United flights. On awards, United doesn’t collect fuel surcharges on Lufthansa flights.

But there is no transitive property of miles.

On awards, Singapore DOES collect fuel surcharges on Lufthansa flights.

US Airways/American Airlines

Where even more people can get confused is with partners of US Airways and American Airlines. Legally the companies have merged, but the two airlines and their loyalty programs won’t integrate until early 2015.

Until then, they maintain separate award charts and partners.

American Airlines has a host of awesome non-alliance partners like Alaska Airlines and Etihad that US Airways miles can NOT book.

US Airways has some fantastic partners like Air China and South African Airways that American Airlines miles can NOT book.

The general rule for all things related to award bookings is that the rules of the miles you are using control. Look up the partners of those miles; look up the rules of those miles; ignore the partners and rules of that type of miles’ airline partners.

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