The parent company of InsideJapan Tours and InsideAsia Tours joined the global movement to "balance profits with purpose".
The certification comes after a rigorous process in which Inside Travel Group produced evidence of its socially and environmentally responsible practices across all areas of the company.
"This is a great day for Inside Travel Group," said co-founder Simon King. "The full process has taken us almost two years to complete, but it is only the start of a longer journey of being a better business for our suppliers, customers, partners, and staff, as well as the communities and environment we work in.
"As a long-haul tour operator, we can’t and won’t shy away from the climate impact that travel has."
