Any new or materially changed recording must be provided with a new ISRC.
Each distinct recording should be assigned its own unique ISRC.
An ISRC can be assigned retrospectively too. If a recording was released without an ISRC one should be allocated before it is re-released.
If a recording has been materially changed since its original ISRC was assigned, it will require a new ISRC.
A material change is where the musical content of the recording has changed, such as:
- Different versions, for example having differences in playing time
- Different mixes/edits
- Creating a new surround mix from recorded stems
- Restoration of a historical recordings that involves creative input
