Some differences between a memo and a letter are:
- Memos are internal correspondence within an organization, from people to people or from department to department.
- Letters are external correspondence to or from outside the organization.
- Memos do not require mailing addresses.
- Letters require the addresses of the sender and the recipient.
The content of both a memo and a letter should be equivalent in content, being courteous, concise, and to the point.
