Benedict’s answer to “How many books will there be in the series Benedict? I just got done with your fourth book. Going t…” > Likes and Comments

Ah good. As long as you have that figured out. I'm all in! Hehe
Thanks for replying :)

He's confirmed that the final book in the series will be Alex Verus #12. That's according to the Feb 14, 2020 post on his blog. It is planned for release in 2021.