Sample Apology Letter to the Supervisor for Poor Performance

To
(Receiver’s Name)
(Position)

Dear Sir,
I would like to express my deep regret and heartiest apology to you because of my poor performance at work. I know that I am coming in late and not completing my work on time. For this kind of inconvenience, I am truly sorry. I also take full responsibility for this.

At last (Mention a Day) you told me to complete some important documents within 3 days. You also told me that you have an important meeting on Sunday. I was working with your files. Suddenly I was feeling not well. Then slowly I was feeling very sick. Then I called peon and told him about my sickness. He called a doctor. The doctor told me that it was a minor heart attack. He prescribed me some medicine and told me to complete bed rest for 7 days.

After I came into the office, I heard about the meeting. I heard that you feel very ashamed at that time. But you are smart enough to deal with this problem and you did it. All of us know about your merit and smartness. I am also thankful to you because you didn’t lose your patience. I know I deserve punishment but please consider it as my first fault and forgive me. I promise you the next time it will never happen again.  Please, sir, give me a chance to prove myself and my promise. This time, I will not let you down. I assure you.

Sincerely yours,
(Your Name)
(Your position)
(Name of the Company)