The article discusses the modelling of household financial behaviour. Synthesis and analysis are used as a general scientific method of scientific cognition. The purpose of the study is to consider possible stages of modelling households’ financial behaviour to achieve households’ financial sustainability in the face of endogenous and exogenous factors of influence. Financial behaviour should serve as an instrument to help define the financial potential of a household, link it to consumption and non-consumption needs, and ensure financial sustainability in adverse circumstances. The methods of modelling the financial behaviour of households are defined. The interrelation of the stages of the household life cycle and the modelling of its financial behaviour by combining risky and risk-free financial instruments is substantiated. According to the study, ensuring financial sustainability is one of the positive results (efficiency) of households’ financial behaviour. Moreover, further research should use elements of correlation and regression analysis to rank risky and risk-free financial instruments by the strength of their impact from least to greatest.