An exemplary system and method are directed to processing dial strings. A dial plan may be parsed into a plurality of expressions, each including at least one expression element. A rule associated the at least one expression element may be identified and added to an array of a finite state machine. Upon receiving a digit input, a match result indicating whether the digit input matched a corresponding expression element of each expression is determined based on the applicable rule. Expressions may be removed from consideration based on the match result. Digit inputs may continue to be received and match results may be determined based on successive expressions until either a match is determined or no further expressions are available for consideration. The match status may be reported based on the match result.