|Ordered||16 Jul 1942|
|Laid down||25 Aug 1942||Flender Werke AG, Lübeck (werk 329)|
|Launched||17 Jul 1943|
|Commissioned||4 Sep 1943||Ltnt. Hans Hellmann|
|Successes||No ships sunk or damaged|
Scuttled on 5 May 1945 in the Gelting Bay. Wreck broken up in 1947.
Men lost from U-boats
Unlike many other U-boats, which during their service lost men due to accidents and various other causes, U-903 did not suffer any casualties (we know of) until the time of her loss.