Because both definitions seem strikingly similar, why have two terms in the first place? Years ago in the 1800’s, the term “comptroller” arose from a careless misspelling of the term “controller.” From then on, the spelling, along with the duties of a regular controller, stuck and the term “comptroller” became a similar term referring to a financial officer in the government sector.
While in the United States, where capitalism seems to have caused a consolidation of the terms controller versus comptroller, the term “comptroller” has developed a slight difference in the European sector. A comptroller seems to oversee the overall costs that go into the services a company is providing. On the other hand, the “controller” is concerned with the bottom line; more specifically, the costs that are associated with the final product within a company. Because the controller is more concerned with the bottom line at the end of the day, his job seems to carry a little more weight financially.
-- WIKI CFO
The term "comptroller" dates back to the 1800s. It comes from the misspelling and misuse of the word "controller," derived from the Latin word, "contrarotulator," which means "keeper of a duplicate roll." People mistakenly linked the title with the French word "computer" and the Latin word "computare," which both mean to count or compute.
Although the label "comptroller" has gained popularity, many argue it is incorrect. Consider an 1896 editorial in The New York Times that urged "that the official title Controller, in all laws, public records, and documents, be spelled Controller, that being historically and etymologically the true and right spelling; and that the false and offensive form 'Comptroller,' born of ignorance and continued in darkness, be discarded."
-- Cornell University