Hi, I am a non resident alien working for an international organization under a G 4 visa.
I only receive income from my employer (the international organization). Do I have to file a tax declaration?

Thank you,

Your income is exempt from federal income tax. Still you must file nonresident tax return and Form 8843. By claiming treaty exemption, your taxable income will be nil.
Read: Your U.S. Tax Return: U.S. Tax Filing Requirements for Non-Residents (http://taxipay.blogspot.com/2008/03/us-tax-filing-requirements-for-non.html)

Your income is exempt from federal income tax. Still you must file nonresident tax return and Form 8843. By claiming treaty exemption, your taxable income will be nil.
Read: Your U.S. Tax Return: U.S. Tax Filing Requirements for Non-Residents (http://taxipay.blogspot.com/2008/03/us-tax-filing-requirements-for-non.html)

Thank you,

Now, before I got the G 4 visa I had an A-2 Visa for a number of years, as I previously worked at my country's Consulate. I did not have any other income. Do I also have to file a form for those years? Are there any fines or penalties for not having filed in previous years?

I am not sure, but it appears that you are required to file during A-2 as nonresident.

The interest and penalty is based on tax due. So if there was no tax due you will not have interest or penalty except may be for non filing. But it is safe to file as IRS may send you a letter even after couple of years, and then it will be more difficult.

Thank you,

Now, before I got the G 4 visa I had an A-2 Visa for a number of years, as I previously worked at my country's Consulate. I did not have any other income. Do I also have to file a form for those years? Are there any fines or penalties for not having filed in previous years?

What are the forms that I have to use to file the Non resident tax return?

If you need to file, the form to file is 1040NR or 1040NR-EZ.

Form 8843 is NOT required for a G visa holder.

If you need to file, the form to file is 1040NR or 1040NR-EZ.

Form 8843 is NOT required for a G visa holder.

Thank you

Someone told me that I might to file form 8233. There is a lot of misinformation when it comes to these special situations.

Appreciate your help

You only file Form 8233 if your situation requires a detailed explanation of the treaty position you are taking.