Nuki makes retrofit smart locks that mount over an existing European cylinder, so a door can be upgraded without replacing the lock. The hardware is Austrian-made and widely used across Europe.

For rentals, Nuki offers a dedicated Smart Hosting tier: self check-in, guest access driven by the reservations in your property management system, and priority support.

Hardware starts at €149 for the Smart Lock Go. Smart Hosting is €69 per year per lock and comes with a 30-day free trial.