This article gives the first large‐scale assessment of business partnerships in England and Wales using business records within the population census for 1881. It seeks to understand the variety of ways that ‘partnership’ was used: explicit partnership, ‘de facto’ partnership, ‘joint’ activity, and asset ownership together. The article confirms that partnerships were chiefly between two people. Complexity and transaction costs largely precluded larger size and squeezed the partnership into a ‘middle ground’ between the sole proprietor and the corporation. The main size contrast was between farms with small employee numbers, and larger non‐farm business partnerships. Generally differences in the gender of business owners have greater salience than sectors. Few female business partnerships employed more than four people (mean 3.4), while male partnerships ranged up to several thousand employees (mean 33.6), and 18.6 for mixed gender. While many women were involved in businesses, their opportunities remained restricted, and most were in partnership with male partners. Family structures were important, with three‐quarters of all identifiable partnerships having some form of family relationship, with a strong preponderance of single women in female‐only partnerships, married men in male‐only partnerships, and widows in mixed gender businesses.