to incorporate now or later ?

Do you have to an existing business to incorporate ?
Or can you incorporate now and open the business later ?

Answer

You can form your limited liability company anytime.

Some states have annual franchise taxes (like California), so it wouldn't make financial sense to form your LLC years in advance of actually operating your business.

In fact, it's far preferable to form your LLC as early as possible, as the limited liability protection does not come into effect until your LLC is formed, and it is NOT retroactive. In other words, you can be held personally liable for "corporate" acts that occur before your LLC is legally formed.