NCP mark - New Chelsea Porcelain Co. England

The lovely teapot below was made by a company called 
New Chelsea Porcelain Co. (LTD).

The back stamp was used around 1912, according to Geoffrey A. Godden (Encyclopaedia of British Pottery and Porcelain Marks 1964, p.464). The manufacture was located in Longton and founded in 1912 (renamed in 1951 to New Chelsea China Co. Ltd.).

See also an article on POTTERY histories