Can I claim the aditional child tax credit if I'm self employed for the 2012 year.

I have ITIN number not SSN.
I have 4 children (two of them have SSN other two have ITIN)
I filled past years as married jointly, I was employee and got W-2, filled 1040
Every year en received tax refund for my children (4,000 or little less).

Now I work by myself and I don't have W-2 anymore.
The job I do is gardener, working for different people I can not get 1099.
They pay me in cash.

A local tax preparer told me there is no reason to file a tax return this next year since I won't be entitled to the Aditional Child Tax Credit as before, because I don't have a SSN, only the ITIN. And adittionally I have to pay "Self-employment tax"

Your tax preparer is wrong; you WILL qualify for the Child Tax Credits even under an ITIN on self-employment income even with an ITIN.

Now, you cannot legally work as a self-employed person on a work visa, but that is an issue with the USCIS, not the IRS.

If you need professional help filing, email me at the address in my profile (if you cannot see the email address below).