Iglu.com founder Richard Downs has joined experiential travel specialist as chair to drive the operator's "next phase of ambitious expansion".
NITGBs said the funding, which has been led by Maven Cognition, will power its growth into new destinations while accelerating investment in its technology.
This, it said, would make it "faster and simpler" for travel agents to discover, package and book its itineraries, driving a new era of "agent-led experiential travel".
Downs founded Iglu in 1998 and grew it into one of the UK's largest online agency businesses; it was acquired by Flight Centre Travel Group for upwards of £100 million late last year.
Carol Savage, founder and chief executive of NITGBs, said: "Not in the Guidebooks was created to connect travellers more meaningfully with the places they visit and the people who live there.
"This investment and the addition of Richard as chair put us in a strong position to move faster — into new destinations, with better technology, and with an even stronger offer for our agent partners.
"We want to be the easiest, most compelling experiential travel business for agents to work with. That's what this next phase is all about."
Downs added: "Not in the Guidebooks has built a highly differentiated proposition in a part of the market that is seeing strong and sustained demand.
"The combination of a curated product, a scalable agent distribution model and a clear focus on immersive travel creates a compelling platform for growth. I'm excited to be joining the business at this stage and to support the team in delivering its next phase."
