Bernhard Frerking was born in Hanover on 1 December 1912 as the son of Bernhard and Marie Frerking. On 1 May 1933, he joined the Nationalsozialistische Deutsche Arbeiterpartei (NSDAP) in the Gau Südhannover-Braunschweig. His membership number was 2313093.
Between 1933 and 1935, Frerking attended Dortmund to study at the University for Teacher Education. He had also been a member of the local Sturmabteilung (SA) since 1934 at the latest. Frerking completed his studies as an Organist und Lehrer für den Musikunterricht an Volksschulen. He then worked as a teacher and organist in Latferde near Grohnde/Hameln-Pyrmont. From June 1936 he was also the part-time choirmaster of a choral society.
On 1 August 1936, he married Marlies Marckmann. They had three children (1937, 1939 and 1944). In the same month he was drafted into military service in the Field Artillery in Fallingbostel. During the war, Frerking was deployed in Artillery Regiment 216 from 1940, first on the Western Front, and later between 1942-1943 on the Eastern Front. Frerking was last deployed as a Lieutenant-Colonel and fire control officer at the Atlantic Wall in Widerstandsnest 62.
Frerking was the superior of Heinrich Severloh. Severloh gained notoriety as the 'Beast of Omaha': as the machine gunner of Widerstandsnest 62, he killed hundreds of American soldiers who landed on Omaha Beach as part of Operation Overlord. Severloh was convinced that Frerking saved his life with the order, "You jump next!" when their fighting position could no longer be held.
On 6 June 1944, Frerking was killed by a shot in the head while trying to retreat from the Widerstandsnest. He was initially buried in the St. Laurent-sur-Mer cemetery. Later he was transferred to the La Cambe war cemetery and today rests in block 7, row 3, grave 89. In the 1950s, his mother asked the Volksbund Deutsche Kriegsgräberfürsorge e.V. several times for a grant to visit her son's grave, which was finally allowed when she proved that her son had been a local group leader of the Volksbund.