Hi,
I have a L1 Visa and came here in Jan-2011 on a intracompany transfer with my wife and son on L2 Visa. I have to go back to my home country in Jan-2012. I have the following questions

My wife does have SSN but my child does not have so I have to apply for ITIN for him.
Please let us know whether I can apply for it now itself or I have to wait till I get my W2 form in Jan-2012. My W2 form will come only in 1 st or 2nd week of Jan-2012 and I might have to go back to my home country in Jan-12.
Hence I thought I would apply for ITIN for son now. Is this okay. If yes, what is the documentation I need to support while filling up the W7 form. I do not have any previous return filed in US as I came only in this year.
Do I need to submit original documents (like passport ) or a photocopy will suffice?

You can not apply for ITIN now. You need to attach completed W-7 forms in front of your original tax return. IRS will allot ITIN and then process the tax return.
With ITIN you need notarized copy of passport of your wife and son. If you are unable to complete your tax return before you leave U.S. may be you should get copies of passport notarized in U.S. Then you can mail completed return from your home country.

When you have the passport photocopy notarized, make photocpies of the visa page and get that notarized as well. The visa page, with its dated entry and exit stamps, offers clear proof that the child spent time INSIDE the United States in 2011.

Further, get FOUR complete copies of both the passport and visa picture pages notarized.

The reason is simple: the IRS seems to have a much higher failure rate for issuing ITINs on tax returns if the return is filed from a foreign country. Many of my clients have had to re-submit a complete packet (Form W-7, notarized paperwork, tax return). When that happens, having an extra set of documents which were notarized in the United States can mean the difference between getting the refund in a few weeks versus waiting up to a year for the money.

Finally, do NOT close your U.S. bank account!

It is much easier to have the refunds from both the federal (and, if applicable, the state) tax return direct deposited into your U.S. bank account. Refund checks which are mailed to foreign countries have a BAD habit of mysteriously disappearing, and the process for getting those checks replaced is painful, tedious and can take YEARS! Once the refund is direct deposited into your U.S. bank account, it is a simple matter to have the U.S. bank transfer the money to your home country bank, and then close the account with an email.

If you need professional help filing your 2011 tax return, email me at [email protected]. This IS what I do!