Monitoring is usually deductible now; installed equipment may need capitalization. The result turns on whether you bought a service, a low-cost stand-alone device, or an integrated building system.
The expense-specific result is below. The shared BAR test, de minimis safe-harbor rule, and source guide live on the deductions hub so they are not repeated on every expense page.
A worked classification for security systems
A landlord pays $360 for annual monitoring and $4,800 for a wired alarm and access system. The $360 goes to line 19. The installed system is capitalized, generally over 27.5 years.
Records that support this treatment
Keep the monitoring contract, equipment list, wiring scope, installation invoice, business-use allocation, in-service date, and safe-harbor election if used.
Keep the invoice, the decision, and the Schedule E placement together. The broader rental property deductions guide and the Schedule E walkthrough cover the full return.
This is general information for organizing rental records, not tax advice. Elections, entity structure, mixed use, and the exact unit of property can change the answer. Bring the invoice and the underlying facts to a CPA before filing.