Codeshare baggage
Through ticketing does not always mean that all carriers involved within that one ticket will accept the same baggage allowance. I travelled Heathrow-Auckland on Air New Zealand and returned Auckland-Beijing-Heathrow on Air New Zealand to Beijing and then British Airways. My ticket was an ANZ one and baggage allowance stated as 23kgs on ANZ sectors and 'see carrier' against the British Airways sector. My return from Auckland was with 2 hold baggage items weighing a total of 12kgs (yes, twelve) and they were tagged through to Heathrow. On checking in for the flight from Beijing, I was told that British Airways allowed only 1 bag and as I had 2, I was to pay the additional charge. After 'discussions' lasting over an hour, they finally permitted me to travel without any extra charge.