A process in the industry where a wholesaler needs an amount that is the difference among the manufacturer's price to the wholesaler and the contract price to the resale customer. The real chargeback happens when the wholesaler sells the manufacturer's product at contract price that is under wholesaler acquisition cost (WAC). Especially evident in pharmaceutical industry. In electronic commerce, a charge back is a reversal of a credit card transaction, which is generally initiated by the card issuer as requested by the cardholder. It may also be requested by the merchant. Charge backs generally occur due to fraudulent activity on the card (real / perceived), due to customer disputes, or from other authorization issues.