I've been looking for an answer to this for a while now since various sites I've looked at contradict one another or claim to know nothing. Anecdotal evidence suggests that the level requirement is Lv. 35 while I've seen friends at Lv. 25 initiate and participate in Raid Battles with no problem whatsoever, so what gives? I'm Lv. 20 right now, and I'd like to be able to join in on the fun, but so far, the game isn't letting me.
The current requirement is Level 5 and above as of June 30th.