Can I claim a percentage of my cell phone bill as a work expense?

The costs of a cell phone may be a business expense, but only the additional costs in using a cell phone for business are deductible.  The Tax Court has several interesting cases on this.  In one case, the taxpayer paid a flat rate on a phone used for business and personal calls.  The court held that as he paid a flat rate for his personal phone and incurred no additional charges for business use, he has no deduction.  (Ritchie, TC Summary Opinion 2005-181). 

Example from Ritchie:  "Petitioner’s cell phone was a personal phone that he also used for business calls. Petitioner testified that he paid a flat rate, regardless of phone usage. Therefore, aside from the personal expense of the phone, which is rendered nondeductible under § 262, he incurred no additional charge for business use."

If you are an employee, you can deduct the business portion of unreimbursed employee expenses that are required for the convenience of your employer.

If you are independent contractor, you can deduct any business expenses necessary to conduct business.