Originally Posted by
Prospero
I had to revisit the
http://www.flyertalk.com/forum/23593103-post6.html thread to check up on IATA’s Baggage Rule Resolution 302 which standardised baggage policies for passengers flying multiple carriers. Here it says that if the baggage provisions of the different carriers are not the same, the policies of the Most Significant Carrier (MSC) will apply. The MSC is defined as the first operating carrier crossing IATA Areas or Sub-areas.
So in the case of your daughter and son-in-law’s booking. my reading is that the outbound sector in WT+ should have used to calculate the baggage allowance across the entire trip.
IATA 302 in normal case only covers per check in . It does not apply to the entire journey
Under DOT regulations ( which would apply in this case ) the baggage allowance is required to be stated at time of purchase as well as the cost of additional piece
With the economy ticket, it will has specified 1 piece , which is BA's economy allowance
That BA granted extra when using miles to upgrade using points , does not mean that other carriers in itinerary then have to allow for this. IB correctly then allowed 1 extra piece for the person with Emerald status
If this had not been a trip to the USA and IATA 302 did apply, then BA's allowances would have applied to the outbound and then IB's allowances for the inbournd