Although the first boats were completed a few months after the start of World War II in September 1939, none of them were able to participate in the Norwegian Campaign of April–June 1940.

They began escorting convoys and minelayers as they laid their minefields in the North Sea and English Channel in July.

A pair of boats were sent to France in mid-1942 and were part of the escort during an unsuccessful attempt to pass one of the earlier commerce raiders back through the Channel in October.

In early 1943 three boats returned to France where they were twice unsuccessful in escorting an Italian blockade runner through the Bay of Biscay into the Atlantic.

The 1930 London Naval Treaty had a clause that ships below 600 long tons (610 t) standard displacement did not count against the national tonnage limits, so the Kriegsmarine attempted to design a high-speed, ocean-going torpedo boat with a maximum displacement of 600 long tons.

This proved to be impossible as the over-ambitious high-speed requirement demanded use of the same troublesome high-pressure boilers that were being installed in the Type 1934 destroyers.

The maintenance problems with the boilers were exacerbated by the lack of access to the machinery allowed by the restricted spaces of the lightly-built and narrow hull.

The naval historian M. J. Whitley deemed "the whole concept, with the benefit of hindsight, must be considered a gross waste of men and materials, for these torpedo boats were rarely employed in their designed role.

[2] The boats were also equipped with six above-water 533 mm (21 in) torpedo tubes in two triple rotating mounts and could also carry 30 mines (or 60 if the weather was good).

Assigned to the 5th Torpedo Boat Flotilla, T2, T7 and T8 began escorting minelayers as they laid a minefield in the North Sea in August.

On 6 November they departed in an attempt to attack two coastal convoys that had been spotted off the Scottish coast, but they ran into a British minefield that sank T6 and they returned to port after recovering the survivors.

[17] After completing their refits, T2, T5, T8 and T11 supported German forces invading the Estonian islands (Operation Beowulf) in mid-September and then, reinforced by T7, they escorted the battleship Tirpitz, as it sortied into the Sea of Åland on 23–29 September to forestall any attempt by the Soviet Red Banner Baltic Fleet to breakout from the Gulf of Finland.

In November, T4, T7 and T12 successfully escorted the commerce raider Komet through the Channel and into the Atlantic despite an attack by British motor torpedo boats (MTBs).

They were intercepted by a British force of five escort destroyers and eight MTBs that sank the raider and severely damaged T10 which subsequently returned home and was paid off into reserve.

Another attempt was made several weeks later, but failed when she was spotted by British aircraft and forced to return by heavy aerial attacks.

T8 and T10, together with the torpedo boat T30, and Finnish forces participated in a failed attempt to recapture the island of Narvi on 27/28 June.

On the night of 23/24 November, the flotilla, which included T3, T5, T9 and T12, screened the heavy cruiser Admiral Scheer as she shelled Soviet positions during the evacuation of Sworbe, on the Estonian island of Ösel.

[21] T1 and T12 were among the escorts for Prinz Eugen as she supported a German counterattack against advancing Soviet forces near Cranz, East Prussia, on 29–30 January 1945.

The first two were allocated to the United States and Great Britain when the Allies divided the surviving ships of the Kriegsmarine amongst themselves in late 1945, but their navies had no interest in them.