As part of the 2st Torpedoboot Flotilla, the ship got fully operational at the end of 1940. After operations near Jutland and mining operations in the North Sea, T12 was send to France in September 1940 for a short time. After a short visit in Germany, the 2st Torpedoboot Flotilla was relocated to Norway , some of those ships supported the advance of German troops during the invasion of the Soviet union and  some participated in  Operation Cerberus in 1942.  The remaining ships were was part of the torpedo training school in the Baltic Sea until mid 1943.  From  1944, the 2nd Torpedoboot Flotilla was used for escort duties in the Baltic Sea.
T12 had a remarkable fate after the war. Handed over to Russia on 27.12.1945, it was renamed to Podvizhnyy on 26.02.1946. In the late 1940s, a serious accident happened in the engine, further problems with machinery actually crippled the ship.  On 08.04.1953 the ship was disarmed and re-equipped into a test/experimental ship and renamed to Kit in December 1954. In spring of 1954 she was transferred to the Ladoga Lake and hoisted near the Makarinsari island off the western shore of the lake. Being equipped for the nuclear tests, this vessel with another one (ex-submarine chaser) was damaged and heavily contaminated as some nuclear charges were blown up aboard her during 1953-54.
In the mid 1950's such experiments were canceled because of risky high level of radiation. The "hot" ex-torpedo-boat was sunk on the shallow waters off the Makarinsari. On 13.03.1959 the ship was erased from the Soviet navy lists. In Summer of 1991 the  "cooled down" ship was raised and towed to the local naval base. Later she was scuttled in other area (exact location unknown).