The Greenland Government requires expeditions and/ or yachts to have a permit when off the ”beaten track” defined on their website www.naalakkersuisut.gl which also explains in detail the process.
This process requires plenty of time but is not onerous and you should allow 8 months. In addition to completing the application form with a detailed plan you require a Radio Licence and a Firearms Permit from other Greenland Government departments.
Additionally you require Search and Rescue Insurance which despite considerable research we were only able to find one company who would sign to the Greenland Governments terms. They are www.forsikring.gl based in Greenland and very helpful but expensive as an indication our insurance was circa £4k. Each individual will also require their medical insurance which can be difficult to obtain.