My question involves a definition of NY income source. I lived in NY through February, 2009, the moved to Rhode Island. I have a consulting business which I operate out of my home. This business involves writing educational grants for school districts. My only client in 2009 was Erie BOCES which is a quasi-government entity in western NY. I signed a contract to consult for BOCES in April (after I had moved out of NY state). The work I did consisted of 2 two day trips to Buffalo, NY where I interviewed clients and did data collection. The actual grant writing took place at my home in Rhode Island with all other client communication taking place via telephone and email. I'm confused as to how I need to treat my income from this job. I live and work in RI but my client is in NY. Is this considered NY income or not for income tax purposes?

If you were resident of NY in 2008, it will be difficult for you to prove that you are not resident of NY in 2009. NY will want you to tax on your worldwide income for 2009.

Also, since you are living in Rhode Island from Feb 2009, Rhode Island will also tax you.

So may be you should keep track of number of days spent in NY and in Rhode Island to figure out NY income and Rhode Island income. Your U.S. Tax Return: Working or Living in Two or More states

I know precisely the number of days lived in each state and I earned income in both and know that I have to pay each state for income derived while a resident. But that is not the question.
I ran a consulting firm while a resident of Rhode Island but my client is based in NY. Other than 2 short visits to NY, all the other work was done from my home in RI. However, the company that paid me is in NY. What I'm trying to determine is whether NY tax has to be paid since the company which paid me is based in NY or whether the income is RI as I live there and almost all the work done was done from my home in RI.

While posting my reply, I missed what you said "..2 two day trips to Buffalo, NY."

If you lived and worked in Rhode Island, the income earned during that period is Rhode Island income irrespective of the fact that the employer is based in NY.