I am Juan from Mexico entered and working in US from Nov '06 through L1A visa. My spouse(not working) & two kids (less than 3 years) joined me in Nov '06 through L2 visa.

This is our second visit to US since 2001-2003. I have a SSN, my spouse has an ITIN from her previous visit 2001-2003 and my kids do not have an ITINs. I need to file my returns for 2006 jointly and please assist me in doing this.

I was planning on filling out the 1040A and W7 forms plus attaching the W2 form from my employer, Is this correct?

What is the substantial presence test? How does that apply to me?

I was also thinking on filling out the following forms Moving Expenses F3903 and Child Tax Credit F8812. Are these forms applicable to me?

You can file jointly with your wife and both choose to be treated as resident aliens. This will make it possible for you to claim the Child Tax Credit for your two children.

There are two catches. First, you must declare and pay tax on ALL the income you earned in 2006, whether it was earned in the U.S. or Mexico. Second, you have to wait until mid-June before you can file, as you will not meet the Substantial Presence Test until then.

Alternatively, you can file as a non-resident alien (Form 1040NR) and pay taxes ONLY on the U.S.-based income. Because you are from Mexico, you can claim your wife and spouse as dependents. That return can be filed immediately.

You CAN claim moving expenses using Form 3903.