This paper investigates the role of information asymmetry in how financial decision-making responsibility is allocated within households. Using data from the China Family Panel Studies (CFPS), we document that when only the wife has access to the Internet, the probability of her taking primary responsibility for household financial decision-making increases significantly. Conversely, when only the husband uses the Internet, this probability decreases. Mechanism analysis shows that Internet access expands individuals’ access to financial information, and spouses with exclusive Internet access leverage this informational advantage to influence their partners’ decisions through strategic partial information disclosure. These findings indicate that such informational advantages translate into a bargaining power premium within households.