Thanks for sharing your insights,
@Sami Mirza. I hope you'll create a thread later about your end-to-end experience with firstbase. We'll love to know how it'll turn out after they have delivered everything they promised. And also, we wish you the best for your new LLC!
Just to give out some updates on my filing... so it is indeed required to file Pro-forma form 1120, and form 5472 regardless you made a sale or not.
The purpose of filing the form 5472 is to inform the IRS of any transactions that happened between you (as a foreign individual) and your LLC (formed in the US). If you just formed it and did not actually do any business at all (just like my case), you need to include in your report the money you paid to form it (eg: Registered Agent fees, consulting fees, domain names, etc)
Actually, IRS is not interested to know the sales of a single-member, foreign-owned LLC (disregarded entity) because it is not subject to any income tax. Because single-member LLC is considered a sole proprietorship, tax returns are filed with your individual tax report and you are required to comply with that according to your country of citizenship.
Pro-forma form 1120, and form 5472 is filed for informational purposes only (in my case). Even if the business bank account is empty, or you are at a negative balance, you still have to report that. By the way, you must keep records of all your transactions. A really great and FREE accounting app I use is Wave:
https://www.waveapps.com/pricing
Filing with the IRS is also free. You only have to fill the forms as per the IRS requirement correctly and on time. Otherwise, you risk getting a steep $25,000 penalty. For foreign-owned LLCs, you cannot file electronically or use e-filing methods, you have to mail the documents or send them by fax. If you need to mail, take note of the special mailing address that IRS publishes every year in their instructions here:
https://www.irs.gov/pub/irs-pdf/i5472.pdf
Be sure to check before you mail as it may change.
I am quite lucky that the filing due date was moved to July 15, 2020, so I still have time. Normally the deadline is April 15 of the calendar year.
As recommended by some people on this thread, better to consult a CPA as it gets really tricky depending on your case. These are general knowledge I've learned by contacting CPAs for inquiries. I shared it here just to give a very high overview.
Because this is my first-time filing, I paid someone on Fiverr to assist me with filing these kinds of forms.
I hope this helps!