I came to learn about Affidavit of support few months ago and stopped taking under the table cash. I'm trying to bring my spouse to USA and to meet minimum income level for me to do so is about 20k a year.
My question is do you think that if I can pay taxes to those under the table cash which I took for last 6-7 months of this year 2015 and meet the minimum requirement for affidavit of support by the end of year which would eventually reflect on my W-2. Is this possible? If you are an business owner and if you paid Under-the-table cash to him/her, and later if he/she asks you to do so(pay taxes on all cash he got paid for) is it possible? or Is it too complicate? Please help me understand this. Thank you for your time.

You can declare under the table income to IRS and pay taxes, but keep in mind you won't be just paying Fed and State taxes, you will be required to pay Social Security and Medicare taxes as well. Since your employer didn't pay 6.2% SS tax and didn't deduct your share (6.2%), you might be required to pay 12.4% SS tax and ~3% (1.45 +1.45) medicare tax. I am not an expert but it happened to one of my friends. Hope that helps.

Is this possible?................it is possible when to file tax for 2015 in 2016.
if this doesn't work then i know few nepali big shot people who will sponsor you wife for IMMIGRANT VISA, but they will charge for it since nothing is free.

anyways good luck