Not really sure what you are asking. This is from the instructions for Sch C, line 25
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.
Are you wondering about if the utilities are mixed between home and business? Is this a home day-care? There are rules for home day-cares.
Here is a link to Publication 587, Business Use of Your Home
https://www.irs.gov/pub/irs-pdf/p587.pdf
**Disclaimer: Effort has been made to offer correct information; but due to the discussion forum limitations, the poster disclaims any legal responsibility for the accuracy of the poster's response**
