In this phrase, "foreign" means from another state, not another country. A Wyoming LLC is a foreign LLC in Texas, and if it does business in Texas it has to register there, appoint a Texas registered agent and file Texas's reports, on top of Wyoming's. That's foreign qualification, and it's why the advice to form in Wyoming has one exception: if the business will physically be somewhere, form it there.
What counts as doing business
States define it in slightly different ways, but they broadly agree. Doing business in a state usually means:
- An office, shop or other premises there.
- Employees working there, including one remote employee working from home.
- Inventory stored there, in your own warehouse or someone else's, in the states that count that.
- Property owned there.
- Regular in-person services performed there.
It usually doesn't include selling to customers in the state from somewhere else, having a bank account there, using a payment processor based there, holding a meeting there, or having a registered agent there. A company run from abroad that sells into every state but has premises in none generally isn't doing business in any of them for this purpose, and doesn't register anywhere.
What registering involves
You apply to the other state's Secretary of State for a certificate of authority, or whatever that state calls it. The application usually needs a recent certificate of good standing from your home state, a registered agent with an address in the new state, and the state's fee. Once registered, the company files that state's reports and pays its fees and taxes, while still filing Wyoming's.
What a few states charge
If you don't register
A company doing business in a state without registering generally can't use that state's courts to enforce its contracts until it registers, and it owes back fees, often with a penalty, when it does. It may also have owed that state's taxes all along, because registering doesn't create the tax presence; the business activity does. Registering just puts the company on the right side of the rules.
Why to form where the business is
A founder who plans to open a shop in Florida but forms in Wyoming pays Wyoming $102.40 to form and $60 a year, and pays Florida $125 to register and $138.75 a year, all for one company. Forming in Florida means paying Florida alone. That's why every state page says a state is right for you if you'll actually be there, and Wyoming is right if you won't.