The institutional unit is an elementary economic decision-making centre characterised by uniformity of behaviour and decision-making autonomy in the exercise of its principle function. A unit is regarded as constituting an institutional unit if it has decision-making autonomy in respect of its principle function and keeps a complete set of accounts. Autonomy of decision in respect of its principle function means that a unit must be responsible and accountable for the decisions and actions it takes. Keeping a complete set of accounts means that a unit must keep accounting records covering all its economic and financial transactions carried out during the accounting period, as well as a balance sheet of assets and liabilities.