A full set of rules of procedure, drawing upon the provisions decided by COP 17, was approved at COP 18. At its second and fifth meetings, respectively, the AC further elaborated on these, also taking into account a decision by COP 19 to replace the positions of Chair and Vice-Chair of the Adaptation Committee by the positions of Co-Chairs.

Upon a recommendation by the UN Office of Internal Oversight Services to harmonize the provisions in the rules of procedure of the UNFCCC constituted bodies, the AC, after its 19th meeting held in March 2021, agreed to amend its rules of procedure to include a provision on conflict of interest.