From what I've read in this thread, your business is a single-member LLC. The IRS considers a single member LLC to be a disregarded entity.
I started a business in 2018 and did not begin earning until 2020.
When the business started earning is irrelevant. If the business was "open for business" on or before Dec 31 2018, then you were required to report all of your business income and business expenses as a part of your personal 2018 tax return on SCH C. Even if the business operated at a loss.
If your business was not open in 2018, but was "open for business" for even one single day in 2019, then you are required to report all business income and business expenses as part of your personal 2019 tax return on SCH C. Again, even if the business operated at a loss.
If you were open in 2018, then you will have to amend your 2018 tax return to include the SCH C. You can not amend a prior year tax return online. You ***MUST*** use the desktop version. With the desktop version of the program you can use TurboTax Premier 2018 or higher. Assuming you used the online version of TurboTax 2018 to complete and file your 2018 tax return, you will need to log into your online account using he same exact credentials you used to complete your original 2018 return, and download the .tax2018 file. (NOT the PDF file - but do get the PDF file for your records so you have a copy of the "ORIGINALLY" filed 2018 tax return. )
After you download the .tax2018 file, then you need to down the TurboTax Home and Business Amendment software at https://turbotax.intuit.com/personal-taxes/cd-download/amend/ty18/ The other version on that website *WILL* *NOT* *WORK* for you. So don't waste your time. If your state also taxes income,then you will be amending the state return too. So if your .tax2018 file includes a state, you will "NOT" be able to open the .tax2018 file for amending until *AFTER* you download and install the state module.Install the federal amending program first, and then from within the federal program click ONLINE and go from there to get the appropriate state module you need, if any.
Take special note that an amended return can not be efiled. The IRS says so. Therefore, after you finish the amending process, that means *YOU* will have to print it, and *YOU* will have to sign the amende return (both the 1040 and 1040X) and *YOU* will have to mail it to the IRS.
When you print the amended return, it will also print a sheet of instructions for *YOU* to follow. The instructions will include the address where you mail the return to, along with what other documents (if any) that you need to include in the envelope with the amended return.
If the state taxes your income, you'll be amending the state return also. A physically separate sheet of instructions is printed for the state return. The federal return and the state return are each mailed by *YOU* to physically separate addresses. So pay attention to detail.
If you need to amend your 2019 return, then log into your online account using the same credentails you used to originally prepare your 2019 tax return. After amending the 2019 tax return, you ***CAN*** e-file the amended 2019 (TWENTY NINETEEN) tax return. You can *NOT* e-file an amended 2018 (TWENTY EIGHTEEN) tax return.
