I'm looking at an LH fare with the following fare rules (for both to/from sectors):

Fare Basis Code: TLXAXNC9/AA1G

V FARE BASIS BK FARE TRAVEL-TICKET AP MINMAX RTG
1 �TLXAXNC9/AA1G T�R 554.00 D30AP T30AP -/� SU/12M AT01


Fare Basis Code: KLXAXZ9/AE1G

V FARE BASIS BK FARE TRAVEL-TICKET AP MINMAX RTG
1 �KLXAXZ9/AE1G K�R 414.00 E19AU T31JL -/3 SU/ 3M AT01
D23JN

The flight is operated by United Airlines.

AC's Aeroplan accepts fare codes T, K and V for United flights, but not K or T for LH accruals. This fare is strangely $50 cheaper than if you got it directly from United, which is listed as a T fare (mileage accruable).

Can anyone advise please what fare basis code should I be looking at for accruals with Aeroplan on such a flight? Thanks

The flights are operated by UA, so you are safe and will earn 100% miles, no need to look any further on aeroplan.com.

The specific information you are looking for btw. can not be found on aeroplan.com or the website of any other Star Alliance carrier. The booking class mapping is embedded within the codeshare-agreement between the airlines. Aeroplan most likely does not have the information what UA booking classes a LH T or K is, UA just tells them that you took flight UA 123 in S or whatever booking class and they credit your account accordindly.

Thanks for this. Is this to say then that all (paid) UA flights earn AP miles no matter the booking class? It just seems strange that a codeshare on a third party airline would cost less than the mainline

Correct 100% miles on all booking classes, and that's determined by the operating carrier, not by the ticketing or marketing carrier. So if you have a flight on United no matter how booked, it's 100% credit for Economy.

And yeah I know it's strange, but the codeshare cuts both ways. Sometimes it costs more, sometimes less. The airline world is a strange place I'll often look for both codeshares and with the operating airline when booking.

The price you pay is determined by the fare published between origin and destination by a given carrier. These fares often allow travel on partner airlines. However, it's the fare that determines the cost, not the choice of partners. If AC is trying to undercut LH they'll lower the cost of their fare, even though that basis may well allow for travel on either carrier.