When someone, say “the beneficiary," is immigrating to the US based on a petition by a relative, a financial sponsor is required, sometimes more than one. The financial sponsor must file an “affidavit of support," either a form I-864EZ or a I-864. (I prefer the I-864, in case a joint sponsor is or becomes necessary, as the I-864, not the I-864EZ would then have been required of the petitioner.) The person filing the I-130, the petitioner, must be a sponsor, but often the petitioner doesn’t make enough money to qualify as a sponsor and so needs a second sponsor, a “joint sponsor." Each sponsor must file their own form I-864. If any sponsor is partially relying on a spouse’s income, both the sponsor and the spouse must complete form I-864A.
The reason the US government requires petitioners to file form I-864 is to prevent the sponsored relative from become a “public charge," a welfare bum. If public benefits are given to the sponsored relative, and if the government requests the benefits be given back, then the government can go to the sponsor and ask for its money back. The key thing to remember here is that the government has to ask for the benefits back. Why would the government ask for its benefits back? Fraud is the basic example. Say I’m your relative and you sponsored me, and I go commit welfare fraud and collect $100,000 in food stamps, falsely claiming to be poor. Well, if I were the government, I’d want my benefits back, who wouldn’t?
How much money does a sponsor need to earn? Well, that depends on a number of factors, but basically more than 25% above the poverty level for the given state, (or just the poverty level for US military personnel). How do we determine the poverty level? Go to www.aspe.hhs.gov and dig around for the 2005 Poverty Guidelines. If the sponsor is married, (say the sponsor’s spouse doesn’t work to keep this simple), and lives with two children, we add the beneficiary to make this a family of five. The poverty level (in the 48 contiguous states) for a family of five is $25,790. Add 25% and we have $32,238. If the sponsor’s income does not meet the requirement, the sponsor’s assets, such as a bank account, stocks, or real estate may be considered in determining the sponsor’s financial ability. However, only assets that can be converted into cash within one year and without considerable hardship or financial loss to the owner may be included, which suggests that the family home shouldn’t be included in the calculation. But wouldn’t you know? What this actually means is that the sponsor can’t use all their automobiles in the calculation. They have to leave one out. The owner of the asset must include a description of the asset, proof of ownership, and the basis for the owner's claim of its net cash value. The calculation for how much in assets is needed to make up for lack of income is simple to determine. Multiply the missing annual income by five, and this is the amount needed in assets, unless it is the sponsor’s wife and or child being petitioned for, in which case multiply the missing annual income by three.
Who can be a sponsor? Any US citizen or lawful permanent resident, over 18 years of age and living in the US or its territories. Sponsor’s residing temporarily abroad must be able to prove just that, (that 'abroad' is temporary, so to speak).
What supporting documents must be filed with the I-864? Basically, the sponsor’s last three years of US tax returns with W-2s, a bank statement, and an employment verification letter clearly indicating how much the sponsor is earning. (They say that only the most recent tax return and W-2 are required, but they don’t really follow this in practice.) If the sponsor is self employed, the sponsor must also include a copy of her business license, and if possibly a letter from her accountant or some other proof of income. It’s almost as if self-employed sponsors have a higher evidentiary standard for proving their income.
When must the I-864 be filed? This depends on whether the immigrating relative in or outside the US. If inside, the I-864 is filed with the I-130/I-485 adjustment packet. If outside the US, the I-864 is not filed until the I-130 has been approved, a visa becomes available, and consular processing has begun.
Disclaimer: This comes as general information, and is not intended for specific applications. I suggest discussing your personal details with an experienced immigration attorney.