The proceedings of the COP and subsidiary bodies are governed by written rules of procedure. However, the COP has not yet formally adopted its rules of procedure, owing to differences in opinion over the voting rule. Discussions are continuing to try to find a compromise. Because all the other rules are agreed, the draft Rules of Procedure are "applied" at each session, with the exception of the rule on voting.

As there is no agreed voting rule, almost all decisions must be adopted by consensus. Consensus is usually interpreted to mean that there is no stated objection to a decision, and is not quite the same as unanimity. For example, a Party may choose not to object formally to a decision, but to ask for its concerns to be taken note of in the report on the session.

The Convention text, however, may be amended by a three-fourths majority vote, if it proves impossible to reach consensus. This is because the Convention itself includes this rule. Once an amendment has been adopted, it must be ratified by three-fourths of the Parties before it enters into force. No amendment to the Convention has yet been adopted.

The procedure is similar for the amendment of annexes to the Convention. However, these amendments do not need to be ratified and come into force automatically, except for Parties that lodge a written objection. Annex I was amended at COP 3, by consensus, to add the names of Croatia, Liechtenstein, Monaco and Slovenia, and to replace Czechoslovakia with the Czech Republic and Slovakia. The amendment came into force on 13 August 1998.

There is no stated rule in the Convention for the adoption of protocols. Therefore, in the absence of an agreed voting rule, these must be adopted by consensus and define their own entry into force procedures. The Kyoto Protocol was adopted in this way at COP 3.

The draft Rules of Procedure set out general rules for debating and negotiating. An important rule is that proceedings of formal meetings must be interpreted into all six languages of the UN (Arabic, Chinese, English, French, Russian and Spanish). Delegates may only speak when they are given the floor by the President or Chairman, and a quorum of two-thirds of Parties must be present for a decision to be taken. The rules also cover the drafting and adoption of agendas and the participation of observers (see section on observers ).

The Kyoto Protocol will apply the Convention's rules of procedure, unless its Parties decide otherwise by consensus. Like the Convention, the Protocol states that amendments to it can be adopted by a three-fourths majority vote if consensus is not possible. Unlike the Convention, however, amendments to the Protocol's Annexes A and B (listing greenhouse gases covered by the Protocol and the emission targets of Parties, respectively) can only come into force after ratification by three-fourths of Parties. Furthermore, any changes to the list of Parties in Annex B must be approved in writing by the Party concerned.