Numbermill was founded in 2014 by seasoned accountant Louise Rayner. Acknowledging the financial challenges faced by freelancers and contractors, she employed her financial expertise to establish the firm. Based in Hemel Hempstead, Numbermill provides customised accounting and consultancy services for its clients, which are predominantly in the recruitment sector. The company’s success has been driven by its strong online presence and delivering educational content. Numbermill also appeared on the FEBE Growth 100 in 2023.