“그런데 여기서 궁금한것이 있는데..세금보고를 분기별로 하는건가요?아니면 일년에 한번 하는건가요?”--->I assume that you are a sole propriertor, as elf employer, NOT an entity,i.e, SMLLC or sole proprietor elected to be taxed as S or C corp, then, it depends;as long as the amount on Sch C of 1040 line 29/31 is $400 or exceeds $400, you need to file Sch C and also as long as the amount on Sch SE line 4 is $400 or exceeds $400, then you need to pay self employment tax to the IRS. I mean if you are filing as a sole proprietor and/or a self-employed individual, you generally have to make estimated tax payments if you expect to owe tax of $1,000 or more when you file your return.If you are filing as a corporation you generally have to make estimated tax payments for your corporation if you expect it to owe tax of $500 or more when you file its return. However, you do not have to pay estimated tax for the current year if you had no tax liability for the prior year;you were a U.S. citizen or resident for the whole year ;your prior tax year covered a 12 month period. “보통사람들 말로는 개인회사는 일년에 한번 한다고 하던데..저는 분기별로 세금보고를 한다고 하는데요..”---->As described above, it depends; you must pay estimated tax for the current tax year if both of the following apply:you expect to owe at least $1,000 in tax for the current tax year after subtracting any withholding and refundable credits OR your withholding and credits are expected to be less than the smaller of: a) 90% of the tax you expect to owe, or b) 100% of your total tax liability shown on the prior year's return. Estimated tax payments are due 4 times each year; Apr 15, Jun 15, Sep 15 and Jan 15.