The article aims at finding out how modern means of communication allowing instant exchange of information, including written messages, have influenced the genre aspects of business correspondence. In the 19th century, business correspondence usually comprised documents made up in order to solve or regulate a dispute or process and to state, observe and define rights, obligations or freedoms of partners. The styles of public and private cases were distinguished. The former was connected with state business, the latter was represented by business letters of all kinds; commercial letters, bonds, receipts, bills, advertisements, certificates, etc. The text of a business letter in the 19th century was divided into three parts: beginning (introduction), main body of the text and end. In the beginning, which is preceded by the recipient’s address, place and date of writing, comes the date of the last or all previous unanswered letters of the business partner or the date of the last letter, the reply to which has not yet been received. Today, the growing volume of business letter correspondence leads to the unification of style and peculiarities of organization of material, to the growing frequency of usage of written formulae and clichés. In contrast to the 19th century, modern business communication more often uses special terminology. One can observe the tendency to the maximum shortening of the letter to the following pattern: “Dear Sir/Madam” - essence of the problem - “Yours faithfully” or “Best regards”. The authors come to the conclusion that the ethical principles and norms of the 19th century remain equally important for the 21st century as well.