2 days ago I booked a ticket from TXL to SFO which although all 4 legs are on BA, the ticket was issued as an 075 (IB) ticket and under their IB codeshare flight numbers. The ticket was much cheaper (only 1 euro plus 266 in taxes) than booking under the BA code and was booked through an OTA.

The most peculiar thing was when I went to manage my booking on BA, they wouldnt let me select my seats and tried redirecting me to the Iberia website, which was unsuccessful.

So, I tried Iberia's website with the PNR and managed to get redirected to BA to select my seats without a problem. Now when I look at my upcoming flights, a new PNR has been created with the same flights, but with the BA flight codes. The original PNR and booking is also intact for now.

Has anyone else had a similar experience?