I was told that in most circumstances, if a Freemasonry group is incorporated it is most likely not regular.
What's important is the recognition. Any jurisdiction that has a chain of recognition that includes the UGLE will point to that and they will need nothing else. This can be direct like the MWPHGLofCT being recognized by both GLofCT and UGLE. This can be indirect like MW Union PHGLofFL being recognized by MWPHGLofCT, by the Conference of Grand Masters Prince Hall, but not yet by the UGLE. It's slam dunk in the states that have local recognition - They get their lineage vetted before recognition is approved.
Most recognized GLs do have corporations, though. They need that for tax ID for their office employees, to be able to hold trusts, to be able to register charities and so on. The documentation packet for GLofIL shows their corporate charter for coolness reasons - It was granted by the state legislature before the state even had an office that charters corporations. But other than historical coolness the GLofIL doesn't need to care about having a corporation.
Clandestine jurisdictions don't have recognition other than among themselves, so they need to put the stress on something else. They claim charters where recognized jurisdictions often don't even have charters. GLs grant charters not receive charters in general. They claim a corporate charter because they have one. Recognized GLs generally have corporations but don't care beyond historical curiosity. Recognition is for inside regular Masonry. Corporations are for outside.
So "it depends".
You ask an IT guy a question. What's the answer? "It depends". Doesn't even matter what the question was. Chuckle. The joke works just as well with Brothers.