ISRCs are assigned by owners of recordings.
For Creators: If you are a self-releasing artist or creator, or if you are beginning your journey with ISRC, you may wish to start here.
For Labels: If you are a record label, help and guidance on obtaining an ISRC Prefix and using it in compliance with the ISRC standard is here.
For Platforms: You can learn about appointment and operation as an ISRC Manager here.