Any new or materially changed recording must be provided with a new ISRC.
An ISRC is assigned to a sound or music video recording before it is released and remains the same for the lifetime of the recording.
An ISRC can be assigned retrospectively too. If a recording was released without an ISRC one should be allocated before it is re-released.
Each distinct recording should be assigned its own unique ISRC. If a recording appears at different bit-rates or on different formats the same ISRC is retained.
Recordings are considered to be different based on differences in the actual recorded content, 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
The general rule is that if the changes being made to the recording involve new artistic input then a new ISRC code is assigned to the resulting recording or version.
ISRCs can also be assigned to:
- Promotional material or hidden tracks
- Podcasts, radio interviews, audio books and wildlife recordings.
If a recording did not have an ISRC originally, has changed ownership, and is being released unchanged by the current rights holder, the Registrant Code should be that of the current rights holder. The Year of Reference should be the year of assignment of the ISRC, NOT the year the recording was made.
An ISRC should be assigned to recordings even where copyright has expired.
Different ISRCs can be assigned to different parts of a recording, particularly if these may be separately exploited.
Different ISRCs can be assigned to:
- Individual movements of classical repertoire as well as the overall work.
- Ring sounds that are digitised audio files, but not ringtones which are control files and have no element of a recording.
The ISRC Handbook sets out most of the rules for assigning ISRC. Further advice concerning when to assign ISRC to DJ mixes is contained within Bulletin 2010/03 — Assigning ISRC to Music Mixed by DJs.