IPI Number - Interested Party Information Number

What is IPI?

IPI numbers are used to identify persons, both natural and legal, used in music rights

IPI numbers are assigned by a central authority through collecting societies (PROs, MROs, CMOs, etc.) We have two kinds of IPI numbers: IPI name numbers and IPI base numbers.

IPI Name numbers

An IPI name number is used to uniquely identify the name of a person. Two people with the same name, both first and last, will have different IPI name numbers, but one person might have several, one for each way their names are written, and also for all pseudonyms, etc.

This results in different IPI name numbers being used for one writer in different databases. One collecting society might use one IPI name #, and another a completely different IPI name # for the same person. This happens quite often with middle names are being written in full in one, and just initials in another. This is where IPI base numbers come in, covered a bit later.

IPI Name Number Format

IPI name numbers are 11-digit sequences. They are not real numbers, so leading zeros should always be used. CISAC and all collecting societies ran into huge issues with CWR because they used 9 digits in CWR headers. Please always use 11 digits. Here are two examples:


The last two digits are checksum digits, they are calculated from the previous nine. They are used to prevent typos during manual entry. All software should validate them, but this is rarely the case. If you are interested in the algorithm, check validators.py from my Django-Music-Publisher project.

IPI Base Numbers

IPI base identifier is supposed to be a universal, unique and unambiguous identifier of a person, natural or legal. They are issued with the first IPI name number a person gets. They are rarely used by publishers, but societies rely on them a lot. One example of this assigning ISWC identifier. Still, it is worth mentioning that whoever has an IPI name number, also has an IPI base number, though they may not know it.

IPI Name Base Format

IPI base numbers are not numbers. They consist of a letter “I”, nine regular digits and a checksum digit. The format is very similar to ISWC format, except for the leading letter.

There are three different ways an IPI name number can be written.: