This paper explains how employers and own account self-employed individuals can be extracted from the original manuscript records of household returns to the population census for 1891-1911. The paper describes the how entrepreneurs are identified in each census, the issues that arise, how miscoding in I-CeM have been corrected, and the method by which each census was cleaned and prepared for subsequent analysis. Detailed discussion covers the quality of returns of employer and own account business proprietor status, how far individuals had two or more statuses identified, the extent of biases in non- response to the employment status census question, and geographical patterns of non-response. The use of occupation descriptors to clean the coding of employers and own account proprietors is outlined as steps towards database construction.