A register of interests, detailing any money paid by suppliers to intermediaries, was today (September 13) called for by the Institute of Travel and Meetings (ITM).
The call by the body which represents buyers in the UK and Ireland came in the second part of its report on Remuneration Transparency.
The first part was published last year.
In the new 27-page document, ITM looks at each sector in the industry and the "levels and types of remuneration at play."
Its evidence is based on anonymous interviews with industry personnel,
The report concludes that "influence at the point-of-sale is diminishing due to a combination of greater automation and corporate control".
But it adds that suppliers and intermediaries should disclose "preferred financial partnerships to their clients in the interests of transparency".
It also notes that any change in the existing remuneration model could lead to higher costs for buyers.
Jamie Hindhaugh, ITM' chairman, said: "Our goal at ITM is to create better relationships to further professionalise this industry for the benefit of all.
"Disclosure of the suppliers from whom intermediaries receive secondary income would provide travel buyers with all the information they need to assess the intermediary influence, not just cost.
"It would be an effective move towards greater partnership and the TMC becoming the buyers-agent, without having to surrender these revenues or disclose deal details."
www.itm.org.uk