Using WRDS to link FactSet to CRSP
About the Linking Method
WRDS has created a linking table that provides historical matching between various FactSet identifiers and the CRSP PERMNO/PERMCO identifier. Additional detailed information about the linking method is available in the FactSet - CRSP Linking Table by WRDS documentation.
The following web query linking FactSet to CRSP is available to users who subscribe to CRSP and either FactSet Fundamental or Lionshares. The linking table is updated annually.