IPI name numbers: what the number on a registration tells you
The IPI name number is the closest thing registration data has to an identifier for a songwriter. It identifies a name. That difference decides how far you can trust a match made with it.
Figures measured 2026-09-15 on the registration data Songlinks reads.
What an IPI name number is
IPI stands for Interested Parties Information, the international system that identifies songwriters, composers and publishers. It is operated by the Swiss society SUISA on behalf of CISAC, and a writer receives a number when they join a collecting society. An IPI name number is 11 digits, and it is always linked to one name: a legal name, or a pseudonym (SUISA).
One person, several numbers
Because the number follows the name, one person can hold several: for a stage name, a spelling variant, a change of name on marriage, or more than one first name. Inside the IPI system those names are linked by a base number that groups a person’s name numbers. The base number is not communicated outside that system.
So, from registration data alone:
- Two different name numbers do not mean two different people. Mick Jagger’s registrations carry two, across three spellings of his name (the example).
- They do not prove one person either. The link between them is the unpublished base number, so any match between two name numbers rests on other evidence: the names, shared co-writers, the catalogue.
- The same name with different numbers can be different people. In a random sample, 8% of songwriter records with a number (81 of 1,018) shared their exact name with a record under a different number.
Many records carry no number
In a random sample of 2,826 registration records, about six in ten songwriter records (1,639 of 2,657) had no IPI name number. A method that matches only on the number never sees them. For those records, whose writer they are has to be worked out from the name and the works.
Companies have numbers too
Publishers and administrators are interested parties, and they get IPI name numbers as well. A number on a record does not by itself show that the record is a person. A self-published writer can appear with one number as the writer and another as their own publishing company.
Using IPI name numbers well
- Treat the number as strong evidence about a name, and weaker evidence about a person.
- Expect several numbers for any writer with a long career, a stage name or a changed name.
- Do not stop at the records that have a number: most do not.
- Check whether a record is a writer or a publisher before counting its works.
Songlinks groups registrations into people using the numbers where they exist and the names and catalogue where they do not, and shows why each record is included. It is in beta, and no person has checked its answers: try a lookup.