20 CFR §655.455

1. (a)Validity period. A TLC is valid only for the period of employment as approved on the CW-1 Application for Temporary Employment Certification. The certification expires after the last day of authorized employment, including any approved extensions thereof.
2. (b)Scope of validity. A TLC is valid only for the number of CW-1 positions, the places of employment located in the Commonwealth, the job classification and specific services or labor to be performed, and the employer(s) specified on the approved CW-1 Application for Temporary Employment Certification, including any approved modifications. The TLC may not be transferred from one employer to another unless the employer to which it is transferred is a successor in interest to the employer to which it was issued.