Stock Changes
Asia-Pacific Economic Cooperation (APEC)

European Commission - Eurostat
Stock changes reflects the difference between opening stock levels on the first day of the year and closing levels on the last day of the year of stocks on national territory held by producers, importers, energy transformation industries and large consumers. Oil and gas stock changes in pipelines are not taken into account. With the exception of large users mentioned above, changes in final users' stocks are not taken into account. A stock build is shown as a negative number, and a stock draw as a positive number.

International Energy Agency (IEA)
Stock changes reflects the difference between opening stock levels on the first day of the year and closing levels on the last day of the year of stocks on national territory held by producers, importers, energy transformation industries and large consumers. Oil and gas stock changes in pipelines are not taken into account. With the exception of large users mentioned above, changes in final users' stocks are not taken into account. A stock build is shown as a negative number, and a stock draw as a positive number.

However, and to be more precise, the definition varies for the application and use of the statistics. For example, in some cases, for oil only stock changes at energy translformation industries and large consumers could be accounted for if there is government control over those stocks.

International Energy Forum Secretariat (IEFS)
As for stock levels, only changes in primary oil stocks of crude and products should be reported.

Stock changes are calculated as the closing stock level minus the opening stock level.

Opening stock level is the amount of primary stocks on national territory, measured on
the first day of the month being reported (e.g. 1st June). Closing stock is the amount of primary stocks on national territory measured on the last day of the month being reported (e.g. 30th June).

Thus, a stock build is shown as a positive number, and a stock draw as a negative number.

Please note that in some other reporting systems, the stock changes are opening minus closing levels. A stock build is then shown as a negative number and a stock draw as a positive number.

There is no unanimity about which calculation to use. However, the international oil industry is in general using the JODI definition mentioned above.

Organisation of Petroleum Exporting Countries (OPEC)
Stocks changes reflect the difference between opening stock levels on the first day of the year and closing levels on the last day of the year of stocks on national territory held by producers, importers, energy transformation industries and large consumers. A stock build up is shown as a negative number, and a stock draw as a positive number.

United Nations Economic Commission for Europe (UNECE)
Stock changes reflects the difference between opening stock levels on the first day of the year and closing levels on the last day of the year of stocks on national territory held by producers, importers, energy transformation industries and large consumers. Oil and gas stock changes in pipelines are not taken into account. With the exception of large users mentioned above, changes in final users' stocks are not taken into account. A stock build is shown as a negative number, and a stock draw as a positive number.

UNSD Energy Statistics Section
Stock change (for producers, importers and industrial consumers) refers to the difference between the amounts of energy in stocks at the beginning and end of the year.