The new partnership will allow agents to book special interest holidays, as well as package holidays to popular destinations including Lapland.
Gold Medal and its specialist brands, including Cruise Plus, will also be able to include the variety of day experiences available from Not in the Guidebooks in package bookings.
Carol Savage, chief executive of Not in the Guidebooks, said: "We are thrilled to be partnering with Gold Medal and Incredible Journeys.
"Given they are one of the largest Independent B2B tour operators in the UK, it’s great that they have recognised us as a key partner to supply them with our extensive portfolio of experiential and sustainable travel experiences and itineraries."
Simon Applebaum, managing director of Gold Medal added: "Not in the Guidebooks gives us access to an amazing wealth of product that is perfectly suited for all our brands, particularly Incredible Journeys."
