Just thought I'd check to see if i could get some clarification so I don't lose out on Tier Points on a trip I'll be booking soon. On BA.com it says that TP and Avios can only be collected on Iberia Express if booked under the IB code. The multi city I will be booking is LHR-MAD-LIS-MAD-LHR. At least one of these flights would be Iberia Express so should I book it on Iberia.com rather than BA.com so the Iberia Express flights aren't codeshares?