Dear [HR Manager's Name], I am writing to inform you of my decision to resign from my position at [Company Name], with my last working day being [last working day, typically 30 days from the date of the letter]. I have appreciated the opportunities for growth and development that this company has provided me, but I feel that it is time for me to move on to new challenges. I will do my best to ensure a smooth transition and complete all pending tasks before my departure. Thank you for your understanding. Sincerely, [Your Name]