1913 and 1914 were boom years for NCR in Great Britain but war in 1914 brought a change in fortune. John H. Patterson was in Berlin when Germany invaded Belgium in 1914 and managed to escape on one of the last trains to leave Germany. Dismissal notices were handed out to all the European staff. The Dayton production fell because the European shipments lessened. The export of machines to Britain did not stop until 1916 and it was only with the entry of America into the war that stopped production of cash registers when the factory changed over to munitions production. All brass and bronze was required for the production of shell cases and it was this that prompted the change from the famous brass machines cabinets to sheet steel.

1921 The class 2000 accounting machine with thirty totalisers was introduced. Models were marketed up to 1973, making the 2000 the longest-lived of any NCR products. Frederick Beck Patterson, John Patterson's son, was named president, and his father, chairman, a year before the founder's death in 1922.

In 1926 NCR became publicly owned and was incorporated in the State of Maryland.

In 1929 The Ellis Adding - Typewriter Company was acquired. The class 3000 accounting machine was developed from the Ellis model having a keyboard to input a narrative description of entries, as well as adding, subtracting and printing features. A new showroom was built at Tottenham Court Road to show off these machines.

1931 Colonel Edward A. Deeds returned to NCR to become chairman of the board. He had left the company in 1915 to help manage Delco, a company formed with Charles Kettering. He also co-founded the Wright Airplane Company with Orville Wright and others.

In 1931 the National Cash Register Co took over the Remington Cash Register Company and at one stroke removed a competitor and gained additional top class salesmen.

Tottenham Court Road 1904-1936