Although the direct effect of flex-work on work-life balance is well documented, previous theoretical explanations and empirical findings related to the relationship have been inconsistent. Thereby, drawing on the job border theory, the role accumulation theory and the human ecology theory, the current study attempts to examine the effect of flex-work on work-life balance by exploring the mediating effect of role conflicts, and the moderating effect of organizational culture. The study was quantitative, and a cross-sectional survey design was followed. The data was collected through a structured questionnaire. The convenience sampling technique was used to select the sample, and the final sample consisted of 450 flex-workers from nine IT companies in Sri Lanka. The data was analyzed using Structural Equation Modelling (SEM) with the aid of AMOS. It was found that flex-work is significantly related to role conflicts, which in turn has an impact on work-life balance. Further, role conflict is found to be a partial mediator, and work-life support organizational culture to be a significant moderator. Finally, it is concluded that though flex-work creates role conflicts which hinder work-life balance, employees could achieve a better balance between work and life in an organizational culture that supports work-life balance. The study makes a major theoretical contribution by addressing the inadequacy of the job border theory in explaining flex-work. The study supports the argument that flex-workers are not border crossers, but rather that they have no borders, and concludes that an organizational culture that supports work-life balance must be considered when explaining the effect of flex-work on work-life balance. It is suggested that managers and practitioners establish such a culture before introducing flex-work to employees.