The IRS assumes everyone has a cell phone. The government gives them away to some. Your cost of doing business over and above your normal need for a cell phone is the portion to deduct. Here are the exact instructions for line 25,ppage C-9, from Schedule C instructions:
Line 25 Deduct utility expenses only for your trade or business. Local telephone service. If you used your home phone for business, do not deduct the base rate (including taxes) of the first phone line into your residence. But you can deduct any additional costs you incurred for business that are more than the base rate of the first phone line. For example, if you had a second line, you can deduct the business percentage of the charges for that line, including the base rate charges.
No mention of cell phones at all. The IRS is not generous in allowing those deductions. Be sure you can prove the extra need versus a basic plan if you are audited. Even then, it may be disallowed, depending on the auditor.
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