Early terminations usually occur when PIs move to another institution.
Once the sponsor has been informed in writing, either a sponsor-specific termination form will need to be completed, or the sponsor will request an early financial report.
Funds paid above the final allowable expenses will be returned to the sponsor. Occasionally, sponsors will request that the university send excess funds to the PI's new institution. This type of request must be in writing from the sponsor on the sponsor's letterhead.
NCURA magazine article covers questions about transferring an award in more detail. NCURA Magazine Article: Award Transfers: Anticipate Issues to Forestall Them (Oct/Nov 2018) Authored by Cornell OSP Grant & Contract Officers Bella DiFranzo and Jamie Sprague. Cornell specifics are on the Transfer an Award page.