A informação consta do item 3.3 do T&C (link):

“3.3 There is a minimum of 1 and a maximum of 999,999 Avios that can be moved between the Linked Member’s accounts in a single transaction. However, AGL and the relevant Avios Programme Operators reserve the right to impose certain limits in the event of suspected fraudulent transactions. For Members holding Blue / Clásica / Green / Basic tier status, an annual limit of 1,000,000 Avios applies to the total amount that may be transferred per Avios Programme between Linked Members’ accounts in any rolling 12‑month period. Avios balances in the Iberia Club and Vueling Club combined in the Avios Wallet are not subject to these transfer restrictions.”

Portanto, fique ligado para controlar o volume de transferência de Avios entre contas, a fim de evitar ultrapassar o teto.