Do I need a landline for alarm monitoring?

No. Modern alarm monitoring signals over broadband, over a mobile network, or both, and a landline is no longer required or even preferred. Mobile-only signalling is a normal choice for properties with poor or no broadband.

This is one of the most out-of-date beliefs in the category, and it comes from an era when the analogue phone line was the only path available.

Today the common configurations are broadband as the primary path with a mobile network as backup, or mobile-only where broadband is unreliable. A mobile path uses a SIM inside the communicator, and better units use roaming SIMs that can select whichever network has coverage rather than being tied to one.

For a rural property, ask specifically about mobile coverage at the building rather than in the area, and about whether the communicator supports multiple networks. That single question resolves most rural signalling problems before they happen.