An example would be nice. I think I found an instance and it looks like the ribbon pricing is based on partner fares, but AS also has their own fare filings to BKK which it prefers to partner fares even when partner fares are cheaper (not too surprisingly). When the flights are AS codeshares, they are using AS fare filings, not partner fare filings. The initial flight listings confused me, as they only listed the QR flight numbers. However, once you add flights to cart, you can see they are actually AS codeshares and thus AS fare filings are involved. The $680 fare listed below in ribbon looks to be a QR fare, but they are only willing to sell outbound flights as AS coded flights with pricier AS fares. The $801 fare below is an AS N basis fare with fare basis code NLR5R1RE. The cheaper $680 option looks to be the QR Q basis QLUSP1RE fare which AS is not showing as an option on website. Since $1424.17 - $1303.71 = $120.46 and $801 - $680 = $121, it's pretty clear the $680 fare is the QR Q fare showing in ribbon listing (note that ITA base fare prices don't include taxes and carrier imposed fees which AS is including in it's ribbon fare prices).








I was able to replicate pricing on ITA Matrix by forcing AS coding on outbound flights.






This is what pricing would be with cheaper QR fare on outbound flights.