OPEC and OPEC+ are both influential groups in the global oil market, but they differ in membership and structure. OPEC, short for the Organisation of the Petroleum Exporting Countries, was founded in 1960 by five nations: Iran, Iraq, Kuwait, Saudi Arabia, and Venezuela. Its main purpose is to coordinate oil production policies among member countries to stabilise prices, secure fair revenues, and ensure a reliable supply to consumers. OPEC today includes 13 member states, mostly from the Middle East, Africa, and South America.

OPEC+, on the other hand, is a larger alliance formed in 2016 that includes OPEC members plus 10 additional major oil-producing countries, most notably Russia, Kazakhstan, and Mexico. The “plus” group was created after the sharp oil price collapse in 2014–2016, when OPEC alone could not stabilise the market effectively. By joining forces with other producers, OPEC+ gained more control over global supply and demand.

The main difference lies in scope and influence. OPEC is a formal organisation with a long history and internal governance. OPEC+ is more of a cooperative alliance without the same level of structure, but it represents a larger share of global oil output, around 55%. Together, OPEC+ decisions often have a stronger effect on oil markets than OPEC alone.