How do I format a resignation letter? A resignation letter is a business letter, so it follows formatting conventions for business letters.State your resignation. Use one of our resignation letter templates. Start with a two weeks notice letter. This will serve as a formal, written documentation of your intent to leave and your transition timeline. Provide the date of your last working day: In the same paragraph, provide the date of your last working day. Download this free resignation letter template below and have it customized for your unique business legal needs today. Share this document. To eliminate any confusion, you can actually include the date of your last day.