The National Accounts by Institutional Sector are defined as a complete and integrated account system, which grasps the economy from an institutional perspective and enables the observation of the main interactions between these economic agents. They consist of a sequence of accounts, including current accounts, accumulation accounts and financial statements, which are linked through balances. These balances provide variables of great value for macroeconomic analysis, such as Gross Available Income, Gross Savings, Financing Capacity/Need, Net Acquisition of Financial Assets, Net Contracted Liabilities, and Balance of Financial Assets and Liabilities, among others. Institutional sectors are grouped into Households, Non-Financial Companies, Financial Companies, Government and Rest of the World.

CNSI is frequently published quarterly in nominal terms and with a 98-day lag for the first three quarters of the year for the measurement period, and 109 days for the fourth quarter. Publication dates are July 6, October, and January, and April 18 or the following business days as applicable. For each new quarterly information, pre-published quarterly estimates for the current year are reviewed following the established revision policy. Also, each annual review updates the quarterly estimates of the figures, consistent with revisions to National accounts and Balance of payments statistics.