First and foremost, your bid withdrawal letter should be honest and professional. Acknowledging that you read their proposal and considered it is a professional and respectful way to start a rejection letter. 2.You typically will not be allowed to withdraw your bid at this point due to an error in judgment without some penalty. This letter is in response to Doe Corporation's invitation for subcontractor bids on the projected south wing addition to Doe's corporate headquarters. Demonstrate to the owner how you made the mistake. Show them material or labor take-offs, subcontractor pricing, etc. To complete the said project.