The PAN number cannot be changed for a particular GST registration. In this case, there is any mistake in the PAN number or a change in the PAN due to a change in the constitution of business (like proprietor to partnership). Then, the applicant will have no other choice except to file for a fresh registration.
It is because the GSTIN number is based on the PAN and GSTIN gets changed. Likewise, if there is a change in the principal place of business from one State to another, GSTIN gets modified. Therefore, it also requires the cancellation of existing registration and application for a new GST registration.