Purchase of seats is only permitted on flights that are operated by Qatar Airways with a Qatar Airways flight number.
If you have purchased your ticket from British Airways for a flight operated by Qatar Airways then you will not be able to select a preferred seat. Please refer to the example given below:
BA7006 20MAR LHRDOH 0800 1745 OPERATED BY QR006
If you have purchased your ticket from Qatar Airways for a flight operated by British Airways then you will not be able to select a preferred seat. Please refer to the example given below:
QR5943 20MAR DOHLHR 0640 1110 OPERATED BY BA122