Consider using a formal Resignation letter for this purpose, which sets out the relevant details, including the effective date of resignation, full details of yourself and your employer and the amount of time you have spent in your job. It also allows you to specify your notice period and to give reasons for your resignation if you want to. Gallery Items tagged Formal Letter. Show all Gallery Items. When writing a formal or business letter, presentation style and format is key to making a good first impression. These templates provide excellent examples of how to structure such a letter, and include sample content to act as a guide to layout.