I have been looking to book an international trip (non US start and end-points A and B) which involves a transfer at a US gateway (G).

I am looking at semi-flex business / first fares, which are refundable or changeable with a fee of GBP 200.

Although there is a through I class fare which is exactly what I want, aa.com keeps defaulting to a marginally lower fare which shows the outbound fare broken down into two parts with two different fare codes: A - G at a different and slightly more restrictive I class fare although still with a GBP 200 change / refund penalty, and then G - B as an L class fare which still seems to book into business class and show on the fare details for the trip as also having the same GBP 200 change/ refund fee.

However, looking at the L class fare on Expertflyer, it is plainly an economy fare. Although there is an "up" business class version of that fare, that is not shown on the trip fare info as the fare code. In itself odd.

However, more importantly, both the L class and the L'up fares are completely non changeable or refundable. I would have assumed that combining an inflexible L with a semi-flexible I would make the I inflexible rather than the other way round, which is what aa.com says is happening.

I can obviously call up AA to check on the specifics of this trip, but it did lead me to the more general question: How reliable is the fare info on aa.com ? More relevantly, can one be 100% sure that what one sees as the fare rules when one books is what an AA agent will see if one calls up to make changes to the booking ?