An IPI (Interested Party Information) number is an international identification number used to identify songwriters and publishers as rights holders. When money is made through publishing, they will send it to this number in your PRO. It identifies you! If you don't have one, theres likely money out there with your name on it!
This number is usually anywhere between 9-11 digits long and is assigned to you by your PRO (Performing Right Organization). You will need to provide your IPI number when you land a track in Library Distribution (Exclusive). IPI is sometimes referred to as a CAE number.
Please note that an IPI number is a separate code from the member ID number or the
account number assigned by a PRO.
You can find your IPI number by either logging into your online PRO account, contacting
your PRO by phone and/or email, or by performing a search in the public repertoire on the
website of your PRO. When searching your name in the public repertoire your unique IPI
number will appear next to it.