What do I need which number for?

The membership number is created for each new member as part of the admission procedure and is automatically communicated to the member by the Members & Partners Department at the same time as the authorisation contract is sent out. It is used for the unambiguous internal verification of the respective member account. The membership number is required for all correspondence as well as for bank transfers, together with the first and last name/company name and the purpose of the transfer.

The IP Base Number is a unique identifier automatically generated by the international database, the IPI system, for each member (IP) who is either a natural person (music creator) or a legal entity (publisher). The IP Base Number consists of 13 characters: Letter i (I), hyphen (-), nine digits, hyphen (-), a check digit. I-9999999-9 and is the main number of each account to which the IP Name Number(s) are attached.

The IP Name Number is a unique identifier automatically assigned by the IPI international database for the civil name of a natural person or the company name of a publisher. IP Name Numbers are also assigned for pseudonyms/artist names and, if applicable, for different spellings of the name or other names (e.g. several first names), so that several IP Name Numbers can be registered for one member.
The IP Name Number(s) are attached to and based on the corresponding IP Base Number. An IP Name Number consists of 11 digits. The last two digits are check digits. 

The contract (account) number is the identification number (ID) of the financial contract assigned to the member on which all bookings are made.