Christina Brazier and Emma Taylor, who both joined Aito in April 2024, are leaving "to pursue new opportunities in their respective careers", the association said.
Martyn Sumners, Aito's Executive Director, paid tribute to Brazier and Taylor for being "a huge part of what Aito has achieved over the past two years".
Sumners said Aito would be recruiting three people "to further enhance the support and expertise available to members" in Brazier and Taylor's stead.
Brazier said: "It’s been a real privilege working with Aito members over the last two years. The passion, resilience and entrepreneurial spirit behind each business are genuinely inspiring.
"I’m incredibly proud to have played a part in launching Aito’s financial protection scheme, a significant milestone for the association, and the time now feels right for me to explore new opportunities.
"I wish Aito every success for the future and look forward to seeing it go from strength to strength."
Taylor added: "It has been a privilege to work alongside some of the most passionate and dedicated specialist tour operators in the industry during my time at Aito. I am grateful for the relationships, experiences and opportunities that have come with being part of such a valued organisation.
"As I take the next step in my career and move into a new role, I would like to thank the Aito team, members and partners for their support and collaboration. I wish Aito every success for the future."
Of Brazier, Sumners said she had brought regulatory and operation expertise, and praised her for her "instrumental" role in developing Aito's financial protection offering, which he described as "one of the most significant developments in the organisation’s recent history".
Taylor, meanwhile, "played a central role in growing the Aito membership, welcoming more than 40 new tour operators, travel agents and business partners during her tenure", said Sumners. "Their dedication to our members has made a real difference, and while they will be greatly missed, we wish them every success in what comes next."
He added: "We’re really excited about recruiting to support the next phase of Aito’s growth and remain focused on supporting independent travel businesses and driving the specialist travel sector forward.”