How do you determine the business portion of a home office internet expense if the entire family uses the internet?

[andyloof]

I'm an independent author with a home office, and I do the majority of my work online. There are four other adults in the house who also use the internet, both for personal and home business work. How do I determine what to take as a Communications deduction?

[Leonard · Accepted solution]

You would apportion the total expense of the internet by the number of users,  20% each in your case.

Then you would have to calculate how much of your 20% usage is business related.  That amount would be a reasonable determination of your business communication expense deduction.