So my parents were a real estate agent (under no company, just received commission and paid no tax - I think it may be different from what happens in the US, we live in Vietnam.) Now how should we prove our financial ability? My parents just came to the tax department and we only have the tax refund of 2018 if we register as a business. Now we have no idea what to do :((
PS: the bank statement is not working cause my parents use money earned to purchase our house. Our bank is blank 
it’s tax return. Im so sorry TT
In your particular case, I would start by contacting your school of interest’s financial aid office and ask for guidance on what to do as an “international” student…further search through the forums here for more info for international students…its a MUCH different process (and more limited financial aid opportunities) than for US citizens…
In general, the only real chance for free money is from the schools themselves, NOT government financial aid; as a result, your best general chance is at private schools that give lots of their own money.
Hope this helps as a start…
How much was your parent income in 2016? That is what goes on the financial aid forms for the 2018-2019 school year.
It doesn’t matter what your parents DID with that money (doesn’t matter if the bought a house). What matters is how much the actually had as income that year.
Much of the above is why many schools don’t give great need-based aid to int’ls. It’s often hard to capture their incomes/assets.