That's why you usually need a permit to sell insurance.

Which Ro Marine didn't have- but they submitted forged documents to Panama and other countries claiming they did. When you have the resources of a nation-state, forging documents from other countries is straight-forward: you can all buy roughly the same stamps, etc. from the same sources, for your own documents. So changing a stamp or two to look like Norway's stamps isn't too difficult.

Getting ports around the world to check back with the originating agency on every document they look at... would be a lot of extra work.