Soldiers who joined the British military during the 18th and 19th centuries filled out enlistment papers. Did officers who bought their commissions also have to fill out enlistment forms?

From the birth of the regular army, in 1661, to 1871, two thirds of officers' commissions were obtained by purchase. The aspiring officer paid the government an agreed sum, often adding a non-regulation premium to the holder of the post he sought to occupy.

The purchase of officer commissions in the British Army was a common practice through most of its history. Commissions could only be purchased in cavalry and infantry regiments (and therefore up to the rank of colonel only). The Royal Navy never practiced the sale of commissions, with advancement in officer ranks being solely by merit and/or seniority.

There were several key reasons behind the sale of commissions:

- It preserved the social exclusivity of the officer class.
- It served as a form of collateral against abuse of authority or gross negligence or incompetence. Disgraced officers could be cashiered by the crown (that is, stripped of their commission without reimbursement).
- It ensured that the officer class was largely populated by persons having a vested interest in maintaining the status quo, thereby reducing the possibility of Army units taking part in a revolution or coup.
- It ensured that officers had private means and were unlikely to engage in looting or pillaging, or to cheat the soldiers under their command by engaging in profiteering using army supplies.
- It provided honorably retired officers with an immediate source of capital.

The official values of commissions varied by regiment, usually in line with the differing levels of social prestige of different regiments. (A farm laborer in 1800 would have earned around 30 to 40 pounds a year. These prices were not incremental. To purchase a promotion, an officer only had to pay the difference in price between his existing rank and the desired rank.)