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How to recognize CDs using Matrix and SID Codes

Every CD has two codes that can be used to uniquely identify it. These are the matrix code and the SID number.

The CD matrix is the long code that often includes a pressing number, barcode, and the name and logo of the CD manufacturer. This information is printed on a CD at the center of the disc on the mirrored side, which is sometimes referred to as the “data” side of the disc. Recognizing CDs through matrix codes and SID numbers has several benefits including ensuring the authenticity of the CD and identifying counterfeit discs. They are also known as the “SID” (Source Identification Code). In this blog, we will discuss why you should always recognize CDs using SID and how you can do so.

The CD contains two different types of source identification codes “SID”.

1.  Mastering SID Code

Mastering SID code is the unique identifier of the plant that manufactured the glass master or stamper used for disc production. The code is composed of the letters “IFPI” followed by a four digit code that begins with “L”. This code is typically printed on the CD at the time of creation and is present on all subsequent pressings of the CD sourced from the same glass master.

It is important to note that mastering SID code does not contain any information about the contents of a particular disc. It only identifies the plant that manufactured the master.

2.  Mould SID Code

The Mould SID code identifies the pressing plant that pressed the CD. This code can be found in the plastic see-through inner ring. The code is very small and hard to read, but it can be read with the assistance of a magnifying glass. The Mould SID code consists of the letters “IFPI” followed by four alphanumeric codes.


How do you find the matrix of a CD?

Finding the matrix of a CD can be done by looking at the physical disc or CD. Matrix numbers can help to identify if it’s the original pressing or reissue of the disc.
If you’re still unsure about your disc’s matrix number, there are helpful discussions available online from experienced users who can help explain matrix numbers. There are also Music Talk forums where people discuss disc identification and matrix numbers. Additionally, some record shops and stores may also be able to provide some insight into the disc’s matrix number if you need more information.


Every CD has a unique matrix code and SID number that you can use to identify it. While the matrix code is present on the surface of the disc, the SID number is engraved onto the center clear plastic layer of the disc. Now that you know how to recognize CDs using matrix codes and SIDs.