Each track needs an ISRC code as a unique identifier to track sales. ISRC enables recordings to be uniquely and permanently identified. ISRC helps to avoid ambiguity and simplifies the management of rights when recordings are used across different formats, distribution channels or products. The ISRC for a recording remains a fixed point of reference when the recording is used across different services, across borders, or under different licensing deals. For more details visit  http://isrc.ifpi.org/en/