Which United Nations Security Council decisions can a permanent member veto?

Permanent members of the United Nations Security Council hold the power to veto "substantive" matters.12

In the Security Council, decisions are categorized as either procedural or substantive:

• Procedural matters: These are decided by an affirmative vote of any nine members. Permanent members do not have veto power over these decisions.12
• Substantive matters: These include significant actions such as the investigation of a dispute, the application of sanctions, or the authorization of military action. These require nine affirmative votes, which must include the concurring votes of all five permanent members. If any permanent member casts a negative vote on a substantive matter, the resolution is blocked, even if it has otherwise achieved the required nine votes.12

Notably, a vote to determine whether a specific matter is procedural or substantive is itself considered a substantive question, meaning a permanent member can use their veto to influence that classification. In practice, however, a permanent member may choose to abstain from a vote without preventing the adoption of a resolution.12