Memos are the most common form of workplace communication, according to the authors of “Handbook of Technical Writing.” Employees and managers use memos for many reasons, including announcements, work assignments — even reports. By definition, all memos are informal. Yet some memos are more casual than others, enough so that a distinction between formal and informal memos can be made. The handbook says the difference lies in both the purpose of the memo and the intended recipient.


Close associates, usually peers, send informal memos. If an everyday relationship exists between supervisor and subordinate, informal memos may also be used. Because familiarity has been established, the tone is more relaxed than in formal memos. Informal memos use given names, often omit background information that the parties are privy to, and often go unsigned and uninitialed. When a memo is to become a historical company document — that is, a record will be kept for reference — a formal memo should be used regardless of familiarity, according to the handbook. Some companies have policies on memo use.

Limited Relevance

The purpose of some informal memos is to transmit information useful only for a limited time. For instance, a work team might use a memo to transmit the time and place of a meeting or to send out a reminder of that meeting. In such cases, the informality of the memo allows the information to be quickly composed, distributed and received with little disruption to workflow.


Project teams usually require someone to serve as an information clearinghouse. Informal memos ably serve the purpose of sending out brief progress updates to keep all project members in the loop until a more formal progress report is required. An amendment to a policy or procedure might likewise be sent out as an informal memo to those who need the information immediately, with a longer, more formal notification to follow.

Emotional Relevance

Informal memos are an effective way to announce events such as office parties or philanthropic efforts. Though such activities aren’t directly work related, they do serve to unite employees and boost morale. A well-written informal memo can be used in these instances to set the tone of the events and build interest. Managers may use memos for motivation or inspiration. For instance, a sales supervisor might share how close the department is to reaching a monthly sales target and announce an incentive to surpass the goal.