The following month, the ship helped to escort another German battleship to northern Norway and returned in May to begin another lengthy refit.

She spent most of the rest of the war escorting ships as the Germans evacuated East Prussia and bombarding Soviet forces.

[1] Paul Jacobi carried a maximum of 752 metric tons (740 long tons) of fuel oil which was intended to give a range of 4,400 nautical miles (8,100 km; 5,100 mi) at a speed of 19 knots (35 km/h; 22 mph), but the ship proved top-heavy in service and 30% of the fuel had to be retained as ballast low in the ship.

[9] Z5 Paul Jacobi and her sister ship Z8 Bruno Heinemann sailed to Norway in April 1938 to test the new 15-centimeter (5.9 in) TbtsK C/36 gun planned for later classes of destroyers.

The division accompanied the heavy cruiser Admiral Graf Spee on her voyage to the Mediterranean in October where they visited Vigo, Tangiers, and Ceuta before returning home.

[11] After she finished working up on 11 October, Paul Jacobi was tasked to inspect neutral shipping for contraband goods in the Skaggerak until February 1940 between visits to the shipyard.

[12] Paul Jacobi and her sisters Bruno Heinemann and Theodor Riedel each carried a company of mountain troops tasked to seize the forts defending the entrance to the Trondheimsfjord.

Her aft torpedo tubes were removed and remounted on a pair of impounded small boats to improve the local defenses.

While departing Aarhus, Denmark for Norway, she fouled a buoy that damaged her port propeller and had to return to Kiel for repairs that took until 24 November.

[17] Paul Jacobi, together with the rest of the 5th Destroyer Flotilla, sailed from Kiel on 24 January for France as part of the preparations for the Channel Dash.

[18] On the evening of 25 January, Z8 Bruno Heinemann struck two mines laid by HMS Plover[19] off the Belgian coast and sank.

[20] Shortly afterwards, the ship joined four other destroyers in escorting Prinz Eugen and the heavy cruiser Admiral Scheer to Trondheim.

Heavy weather forced Paul Jacobi and two other destroyers to return to port before reaching Trondheim and Prinz Eugen was badly damaged by a British submarine after their separation.

[16] On 6 March, the battleship Tirpitz, escorted by Paul Jacobi and three other destroyers, sortied to attack the returning convoy QP 8 and the Russia-bound PQ 12 as part of Operation Sportpalast (Sports Palace), but the ship was ordered back to port that evening.

[21] Two months later, in Operation Zauberflote (Magic Flute), Paul Jacobi, the destroyer Z25, and two torpedo boats escorted the badly damaged heavy cruiser Prinz Eugen from Trondheim to Kiel from 16 to 18 May.

The ships were spotted en route two days later by an aircraft from the Royal Air Force and the attempt was abandoned as the element of surprise was lost.

She screened the battleships Tirpitz and Scharnhorst, as well as Lützow to the Altafjord, closer to the Allied convoy routes to Russia, in mid-March.

Two weeks later, the ship, her sister Z6 Theodor Riedel, and the destroyer Z20 Karl Galster sailed for Jan Mayen island on 31 March to rendezvous with the blockade runner, MV Regensburg.

One bomb struck the forecastle and started a severe fire while four others landed inside the dry dock itself, riddling her with splinters and sinking the ship.

Paul Jacobi was declared operational on 13 November and she escorted the hospital ship SS General von Steuben from Gotenhafen to Swinemünde.

[27] Paul Jacobi was decommissioned five days later at Flensburg and sailed to Wilhelmshaven under British control on 21 May to have her fate determined.

In March–June 1947, she formed part of the escort for the battleship Richelieu as the President of France, Vincent Auriol, visited West and North Africa.

The ship was present in Saint-Malo during the commemoration of the centenary of the death of François-René de Chateaubriand and she visited Bordeaux before returning to Cherbourg on 4 November.