Yes, you can do incidental business in other states. If you were to have a store or sales/service person, you will have to register in the state to become authorized to do business. The answers are very fact specific. What kind of business do you operate? Does it require a license? Is it online or do you have physical locations?
You need to discuss this with a tax and business attorney.
Yes. If o whether you need to collect, and pay to the other states, sales tax. If you have employees,you have to go to those states to do business, you must register (become authorized) to do business in those states. You also need to check with a CPA as to see if you have to file a tax return and/or pay and collect employment taxes, or if a solo, pay estimated tax.
If you are solely a mail order/Internet sales company, sales tax may be an issue, but the other issues do not apply.
IF you ever have to sue a client/customer in another state, a defense to such an action is that you are not authorized to do business.
The foregoing is not intended to be legal advice upon which you may rely as I have not been retained for this purpose.
Yes, you can do business in other states. By way of example, Exxon Mobil Corporation is incorporated in NJ but does business in all 50 states.
If this answer was helpful, please mark it as helpful or as a best answer. This answer is for general education purposes only. It neither creates an attorney-client relationship nor provides legal guidance or advice. The answer is based on the limited information provided and the answer might be different had additional information been provided. You should consult an attorney.