In the country that I’ve been focused on, Ninora, you would send an application to the Petitions Committee. This committe goes around and attempts to get a certain number of votes from citizens to make your company a reality (keep in mind that they don’t go nationwide.) Once they’ve reached a certain number of votes (1,000-2,000), your company is officially instated into the Guilds Cabinet.
If the Petitions Committe fails to reach a certain number of votes, your request to create a company is denied and you have to wait another sixty days to submit another application.
In my world, companies may act independently, but to join a guild, they must go through a similar process as yours.
At the top of the trading food chain is the Royal Advisor of the Treasury.
Underneath the RAT are the various representatives of each guild (Goldsmiths, Tanners, Nutritionists, etc.)
In each guild is a council of company leaders. This is a very rough and corrupt system, as each member has to deal with the balance of keeping their guild wealthy and formidable as others, while also keeping their company's competition low.
Individual, non-guild companies may submit their application once every cycle of the moon (approx. once a month) for revision.
The applications are looked over by the guild council. While most companies are kept out, the council occasionally accepts companies so the RAT will look on them with favor.
Government funding is distributed on the basis of which guild brings in the most taxes for the Treasury. Each company would have to pay taxes anyway, but the companies in the guild are counted as one party.
The government funding is supposedly used to 'Improve the success and nature of the production of x product.' Though it's usually just stuck into the back pockets of the company owners.