Abstract: Electronic data interchange (EDI) documents are validated by creating an inventory of all rules, dynamically adjusting the inventory based upon entity specific rules derived from a plurality of companion guides, determining a profile containing pointers to select rules in the inventory for each companion guide and storing the profile for each companion guide in a storage. A runtime checker can then be used to check a received EDI document with a corresponding rule set, forward the EDI document if the EDI document matches its current rule set and return the EDI document if the EDI document does not match its current rule set. EDI rules may be enforced, for example, by determining entity-specific rules from corresponding companion guides, by expressing each rule in a neutral and machine readable format, by classifying the rules and/or by creating an inventory of rules and pointers to entity-specific rules.