I started a web/video production business with my family -- LLC taxed as a partnership. Two of the partners are in Colorado, which is where we registered as an LLC. The other three partners live in Illinois.
Most of our customers this year ended up being from Illinois -- we produced videos and built websites. On my tax return, I'm interpreting that I owe "replacement" tax in Illinois. I'm just about to mail my tax return, when it hit me: Do I need to register as a foreign LLC in Illinois? Will they accept my tax payment, or mail me a penalty for not registering? Does creating websites/videos for clients in IL constitute doing business? We have no physical address there.
Thanks so much.