“동생 세금 보고를 누나인 제가 대신 세금 보고 할수 있나요 ?”- Why not prepare the return and let his sign and mail it to IRS from wherever he is. Foreign postmarks are accepted. Have any refund direct deposited into his checking account if he wants. Your brother will need to sign a Power of Attorney for this purpose; but that makes you just as liable as his if there are errors, so beware. Also for the past few years, you can even do fill-in forms and file online. So that can be done from anyplace that has internet access. You don't have to be physically in this country.As your brother is an IC getting a 1099, you need to file Sch C / Sch SE, as long as the amoun ton Sch SE line 4 is $400 or exceeds $400, then yu must pay SECA taxes, selfemployent taxes it the IRS.