Business & farm

You would enter the total expenses for the entire home and TurboTax will prorate that amount based on the percentage of the home that was used as home office. For example if the percentage is 10% and total utility bill is $100, TurboTax will calculate $10 for Home office utility expense. 

If you have a separate utility charges for your office(not very common) you can enter the amount next to home office only utility. 

For expenses related to your home office only, you can take %100 of these expenses. 

Utilities include:

- Gas and electric
- Water
- Sewer and septic system services
- Trash removal
- Heating oil

For communications expenses , such as phone lines, cell phones, fax lines, etc. we'll ask you for that information in the General Expenses 

For more information, check: Where do I enter the home office deduction for my business?