Originally Posted by
Innocent Abroad
Does anyone know what is the situation with interlining IB-IB on separate PNRs?
The situation is you can't really know for sure until you ask.
If you are travelling with different tickets, the corresponding allowance for each one will apply. is what the IB website says, but that sounds like jibberish to me. Either you accept the most restrictive allowance for the whole itinerary (i.e. one flight Y, the other J on separate tickets so you can check the Y equivalent the whole way) or essentially IB are saying you need to re-check each time.
http://www.iberia.com/es/luggage/allowance-in-hold/