Dear [Name],

I am writing this letter to express my sincerest apologies for [reason for apology]. I understand that my actions have caused inconvenience and disappointment to you, and for that, I am truly sorry.

I want you to know that [explanation of the situation]. However, I realize that this does not excuse my behavior and I take full responsibility for my actions.

I value our relationship and the trust that we have built over time, and I hope that you can find it in your heart to forgive me. I promise to [action to make amends] and to ensure that this situation does not happen again.

Once again, I am deeply sorry for any harm that I have caused and I hope that we can move forward from this with a stronger and more positive relationship.

Sincerely,

[Your Name]