Methods, computer readable media, and devices for leveraging individual engagement history in account-based marketing personalization are provided. One method may include receiving information identifying an individual associated with a first business and an interaction between the individual and a second business, creating a new entity contact record, determining a global party identifier to be associated with the new entity contact record, updating the new entity contact record to include the global party identifier, calculating a unified lead score indicating a propensity of the individual as a prospect based on the individual, the first business, and the interaction, updating the new entity contact record to include the unified lead score, and, if the global party identifier is associated with an additional entity contact record, recalculating the unified lead score based on the additional entity contact record and updating the new entity contact record with the recalculated unified lead score.