For 1099 contractors & freelancers
Yes, the business-use percentage of your cell phone bill is deductible for 1099 contractors and freelancers.
Schedule C, line 25 (Utilities), or line 27a (Other expenses).
If you use one phone for work and personal life, estimate the share of use that is for business (calls with clients, work email, business apps) and deduct that percentage of the monthly bill. A phone used only for business is fully deductible.
A reasonable method is to review a typical month of calls and data and apply that percentage to the year. Picking 100% for a phone you also use personally is a common audit flag.
The phone itself is deductible the same way, at your business-use percentage. Most phones can be expensed in the year you buy them under the de minimis safe harbor.
Monthly bills, plus a note of how you worked out the business percentage.
In Smart Deductions, this is suggested as Phone & Internet (Schedule C line 25). You confirm it before it counts.
Sources
General information, not tax advice. For your specific situation, check with a CPA or Enrolled Agent.