Originally Posted by alex0683de

In general, you can receive both award and status miles on AA for BA flights, but you cannot earn AA miles for BA flights from London to the US. Conversely, you cannot earn BA miles on AA flights from the US to Europe.

Antitrust agencies on both sides of the pond decided that if AA/BA could codeshare and give miles on their collective flights on these routes, this would equate to unfair competition since they together hold something like 70% of the London-US market.

Again, this applies only to transatlantic flights, a BA flight to Dubai or wherever earns regular status and award miles on AA. Same for flights to Canada, Mexico, the Caribbean - anyplace that is not in the US.

The one exception to the rule are BA flights to the US from Manchester - these earn normal miles as well, since the antitrust issue is only about London.