Originally Posted by
PTahCha
The issue lies within UA and the airport. The bags are transferred through if you were flying through PEK.
Unless we are talking about a difference in semantics, bags are not automatically transferred in PEK on an ID connection. There is a separate area in baggage claim for domestic connecting pax to clear customs. There is no such thing as a bag "drop off" for you to directly proceed through security. Instead, you have to push it through the domestic-style x-ray machine and then check in again with CA. Even if your bag was already tagged to the final Chinese destination, iirc CA will retag it with their own tag.