The rental-business share is generally deductible. Allocate the bill and device cost between rental, personal, and any other business use using a reasonable record.
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 cell phone use
A $1,200 annual plan is 30% supported rental use, producing a $360 line 19 expense. A $1,000 phone used 30% for rentals can produce a $300 business basis, subject to the chosen expensing method.
Records that support this treatment
Keep monthly bills, line assignments, a representative usage sample, rental contacts, device receipt, business-use percentage, and safe-harbor election.
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.