Sometimes it's obvious. If you see "Inc." after the business name, that's a clue it's most likely a corporation.
But you should still confirm it!
There are a couple quick ways you or an assistant can identify or confirm the structure of a business defendant and discover any individuals who could be named as co-defendants.
1. Search the California Secretary of State (SOS) business registration database
You may discover the keyword "Five Cool Guys " pulls up one result for "Five Cool Guys Construction, Inc." Click on it and see the company's address and Agent for Service of Process, and if it's "Active", and you're done.
Don't you at least feel better for confirming it? It took one minute.
But..... you might find several variations on that name, some of which may not belong to your actual defendant, and some of which may be defunct or suspended. You'll have to do a little research now, and that might include identifying some individuals that can be named as co-defendants. Sometimes an identity investigation can help here.
Or..... you may turn up zero results! Make sure you've broadened the keyword search. If you still don't get a hit for this business, that might tell you the company isn't registered in the SOS database.
2. Search the fictitious business name (FBN) registrations in the county where the business is based, and surrounding counties if necessary. These resources are almost all online nowadays, like the FBNs registered in San Francisco County, for example.
Sole-proprietors "doing business as" (dba) a name different than their own, must register FBNs. These people have individual liability for their businesses. For example, Chad Cool, an individual, would be "doing business as" Cool Construction. In that case, this particular business structure is an individual person with sole liability.
Sometimes corporations or LLCs register FBNs too. In that case, you might find "Cool Construction" is owned by "Five Cool Guys Construction, Inc." Now you know that a larger entity is behind this and not a sole individual.
Once you've properly identified the structure and name of your business defendant, be sure to properly name it on the summons.