DO NOT transfer BA Avios to Iberia without book a ticket right away, because they will expire them almost immediately! Here is my demise of 11k Avios moved from BA to Iberia back in April:
Some how my 11k points became muddled with the 50 I had gotten form opening the account back in 2015. Therefore it appeared that it had been over 3 years of inactivity. This very same thing happened to a blogger with 90,000 points!
I was lucky because it was such a tiny amount I was planning to book for ORD to CMI for 5,500 a ticket for two. The plans fell apart and I had forgotten about the points until today. I noticed my account was zero when I was planning to book this wicked cheap flight for two from ORD to DCA:
So beware out there! Iberia, BA and pretty much all of Avios are terrible booking websites full of glitches. I just want to spend these things as fast a possible!