How to become non resident of a State for tax purposes?

income in the new state how can one prove to the CA Franchise Tax Board that one is no longer is a resident of CA and should not be subject to CA State income taxes?

would have earned income in 2 states.

resident in the State?

Easier question first:

If you move in the middle of a tax year (very common), you are considered a part-year resident of each state, and will have to file as such with each state, treating part of your year under resident rules, and part of your year under non-resident rules, respectively, for each state.

That, in fact, is one thing I highly recommend to help establish your change of residency: file a final CA part-year resident return showing the date(s) you (and your spouse, if applicable) moved out of state. Assistance of a professional tax preparer is often a good idea in this situation.

There are are many CA statutory details, such as for military members, long term employment contracts, people who only vacation in CA, etc, but generally, when you make a permanent move from one state to another, you want to create social, business, and financial ties to the new state that are stronger than those to the old state.

There is no hard formula. Factors considered include where your immediate family lives, where you live and spend most of your time, where you own non-rental real estate, where you earn money, where your doctor, church, schools, social organizations etc. are located, where you register and drive a vehicle, and so on.

Before leaving, I also want to mention the concepts of residency and domicile. They are not the same thing. You can be a resident of state based on it being your domicile, based on statute, or both. You can even be considered a resident of two different states, or no state at all, under some less common circumstances. However you always have exactly one domicile at all times from birth to death.

If you search the archives of this group, you will find many, many discussions of this topic, look especially for any of the authoritative contributions by Katie J., who unfortunately has not appeared here in recent times.

The California Franchise Tax Board has a publication that explains what determines whether you are a resident of California for income tax purposes.

FTB Publication 1031 Guidelines for Determining Resident Status - 2012

Bob Sandler

In addition to the other answers I recommend filing a change of address form on the date you cease to be a CA resident. This is only a recommendation, not a requirement.