Free BA (Silver) seat assignments with Iberia FF number?

[jacaranda1]

Hello everyone,

I have an upcoming mixed BA/AA booking (LHR-SFO-JFK-LHR) in J after 1 April 2025. Like many disaffected BAEC members, I am considering crediting all future OneWorld trips to IB given their lower spend thresholds instead of BA. I have BAEC Silver but no status with IB.

If I enter my Iberia FF number on the booking instead of my BA one, will I still be entitled to all the usual BA Silver benefits – especially free seat assignment at the point of booking? Or should use my BA number now, and then call up BA after the flights have been taken to credit the Tier Points / Avios to Iberia instead?

Thank you