Congratulations! You just asked the best question (which is why it's also at the top of the FAQs). You know (or at least should know) your business best, and so that also means you know what liabilities you may face. Make a list. Call up your insurance broker (you have one, right?) and talk through what’s covered and then what isn’t. Are there things out of your control, such as employees? Those are some things to consider. You can read my post on this or watch the video on this topic. It’s very important that you not waste time and money on something you may not need.
An LLC, or limited liability company, is a type of entity that protects its owners and mangers from liability, unless they personally do bad things. Like a corporation, an LLC happens when its Articles of Organization are filed with the state authority. In California, this is an online form. Keep in mind, there are other filings, and then ongoing responsibilities of those managers and members to continue shielding them from liability. And if there’s more than one Member, having a written operating agreement is highly advised. There may also be tax advantages to filing as an LLC.
An S Corporation is a corporation that has made an election (i.e., timely filed a form) to be taxed as a “pass-through”, i.e., the corporation itself is generally not taxed, but all of the taxes for profits and income, as well as for losses and expenses, are passed through to become the obligations of the individual shareholders. There are limitations to what corporations can be S Corporations. For example, S Corporations cannot be owned by more than 100 shareholders or by non-resident aliens. The “S” stands for . . . wait for it . . . small.
You’ve read a lot about that, I’m sure. There can be reasons to form there. Here are two that come up a lot: One, your business is going to have big deal investors who like being in Delaware, sometimes for reason number . . . Two: Delaware law is corporate-centric, efficient, and can provide better protections for the corporation’s officers and directors. But like filing anywhere else, if the principal place of business is in another state, you’ll need to register your corporation (or LLC) in that state as well as a “foreign” corporation/LLC.
I wish the answer to this were more existential, and thus more interesting. Alas, it’s as simple as this: when you duly file Articles of Incorporation, also know as charter documents, with the state official authorized to recognize and process such filings. In California, it’s the Secretary of State. In Delaware, it’s the Division of Corporations. Same for LLCs, except it tends to be called Articles of Organization.