What is “CSID”?

Last Update: August 9th, 2021


CSID stands for “called subscriber information.”


It is used in fax machines as a field for the receiving fax machine. It is very similar to TSID, or “transmitting subscriber information.”

When a fax transmission occurs, the CSID (receiving fax machine’s information) is transmitted to the sending machine. This information can be used in confirmation pages and fax logs.

How to set up CSID

Fax machines and fax software have fields where CSID information is inputted. It is typically the name of the fax machine as well as the fax number where it can be reached.