Recommissioned on 17 June 1940 – as the United States Navy expanded to meet the demands imposed by Neutrality Patrols off American coastlines – "Thomas" was assigned to Destroyer Division 79 of the Atlantic Squadron and operated briefly in training and exercises off the eastern seaboard until transferred to the United Kingdom under the "destroyer-for-bases" agreement. She arrived at Halifax, Nova Scotia, on 18 September 1940 as part of the second increment of the 50 flush-decked, four-piped destroyers exchanged with the British for leases on strategic base sites in the western hemisphere. After a brief familiarization period for the Royal Navy bluejackets assigned to the ship, "Thomas" was officially turned over to her new owners on 23 September 1940. Her name was subsequently struck from the United States Navy list on 8 January 1941.