Abstract: An interactive knowledge based system for monitoring international tax status has a residency status analyzer and a tax treaty analyzer that cooperate to determine the residency status of an individual, based on the individual's visa history, travel to and from the US, and the applicability of any treaty for the individual. The residency analyzer evaluates visa history, travel and days in the US, as well as type of activity and any applicable treaty's tie-breaker rule to determine if residency status is affected and sets indicators accordingly. The tax treaty analyzer performs an income type analysis to determine if income is from employment services, self-employment, or scholarship and fellowship grants. The tax treaty analyzer evaluates the applicable treaty for the presence and terms of a saving clause.