A system is disclosed for processing of electronic product order data from vendors and wholesalers based on pricing contracts specifying qualifying vendors, customers, products and pricing. Product order data is compared with a plurality of pricing contracts established by product manufacturers. Errors in the product order data are identified by comparing the product order data with pricing contracts and proposed or suggested solutions to the errors are compiled. Proposed error corrections in the product order data are electronically presented to manufacturers by way of a GUI computer interface so that acceptance of proposed solutions requires minimal analysis and feedback from the manufacturers. Where proposed error solutions are deemed erroneous, manufacturers are provided a GUI interface mechanism for manual keyboard entry of appropriate corrected data. Sales invoice data is reconciled, once errors are corrected, for automatic posting and payment of rebates to vendors or wholesalers based on pricing terms established in the contracts.