Yes, the business part. The 2025 Schedule C instructions say that if you use your home phone for business, you cannot deduct the base rate of the first phone line into your home, but you can deduct additional business costs above that base rate, and the business share of a second line. The personal share of any phone bill is not deductible. A ProfitDrawer bookkeeping spreadsheet logs each bill under an expense category you choose.
One practical way to find the business share of a mobile phone:
- Review a typical month of calls and data and estimate the business percentage.
- Apply it to each bill.
- Keep the bills and a note of how you worked out the percentage.
Example (example numbers only): a $60 monthly bill used 70% for business gives $42 a month, or $504 for a 12-month year.
Other points:
- Phone service goes on Schedule C, line 25 (utilities), which the instructions limit to costs for your trade or business.
- Business calls made while traveling for business are deductible travel costs (IRS Publication 334, 2025).
- A phone you buy is equipment, not a bill. If you elect the de minimis safe harbor, items up to $2,500 per item or invoice can be deducted instead of capitalized.
- If the same phone or plan is used for business and personal life, only the business part counts.
General information, not tax advice.
Source: IRS Instructions for Schedule C (Form 1040) (2025) · Updated
Tools and spreadsheets for this
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General information, not tax, legal or financial advice. Check the rules for your state and your situation.