1. A method for associating an entity of a contact with a character string, wherein a database stores a plurality of contacts, and each contact has a defined set of entities, comprising: determining, for a first subgroup of the defined set of entities, using a processor, whether the character string comprises a structure associated with the first subgroup of the defined set of entities, prior to any probabilistic approximation, wherein the structure comprises at least one character other than alphanumeric characters; replacing all numerical digits in the character string with a corresponding digit placeholder to generate a blurred character string in response to a determination that the character string does not comprise the structure associated with the first subgroup; and determining, for a second subgroup of the defined set of entities, using a processor, a probabilistic approximation that the blurred character string is associated with at least one of the defined set of entities in the second subgroup by scoring the blurred character string for each of the defined set of entities associated with the blurred character string; and identifying the character string as one of the set of defined entities having a highest score that satisfies a predetermined score threshold.