Does my company have to be a sole proprietorship, or can it be a limited company?

This permit is specifically for self-employed persons operating their own sole proprietorship in Norway. If you set up or work through a limited company (aksjeselskap / AS), you would generally be treated as an employee of that company and would need a different permit, such as the skilled worker permit.

You do not necessarily have to register the company in the Bronnoysund Register Centre before you apply, but you must be able to document that the business is yours and that you control it. Confirm the current registration expectations with UDI for your situation.