Producer and songwriter
For how to split royalties with a producer, first decide whether you are talking about the composition, the master, or both. A sound recording is separate from the underlying musical work, so the split should match the part of the song you meant to share. See producer shares and the royalty split guide.
Cowriters
If you intended one song as a joint work, write it down as soon as you can. US copyright law treats a joint work as a work prepared by two or more authors who intended their parts to be merged into one work, and the authors are coowners of that copyright. The statute does not set the split for you.
Band members
For bands, the same sheet can list every name and the share you agreed on for the song. Keep the record clear so everyone can see who was part of the writing deal. A simple split sheet template can help.
Beat maker sending a file
If a beat maker is sending a file, use the license checklist too. That helps separate a file delivery from the rights discussion and keeps the agreement in one place. You can also review the feature list if you want to see how Splitline organizes records and reminders for repeat use.
Not legal advice. Splitline does not grant a license, clear a sample, or pay royalties.