A circular letter is used to share the same information with a large audience. It differs in purpose from a personal letter, which sends particular information to one or a few recipients. Circular letters are often used to announce new information or to clarify policies. They are somewhat general in topic, since they are widely read. Writing a circular letter of any kind requires a few important steps.
Know your audience. For circular letters, readership is diverse, so it can be difficult to gauge your audience's level of prior knowledge or familiarity with the content that you want to share. However, consider the majority of likely readers when you write, so that your letter is useful to the most people.
Distinguish between internal and external circular letters. An internal circular letter, although circulated to a large group, is still restricted to a group. For instance, a business may circulate an internal letter to employees about a new company policy. In contrast, an external letter would be a letter circulated to all clients or to the public.
Use the tone and voice appropriate for the kind of communication (internal or external) for which the circular letter will function. For instance, a stern tone would be appropriate for a circular letter to all employees addressing tardiness or absenteeism. However, a stern tone would not be appropriate to use for a letter to circulate to clients.
Share only authorized information. Since circular letters are intended for a large audience, they are not suited to disclose confidential information or details not intended for a widespread audience.