Beginning and ending:

1. Dear Sir or Madam, Yours faithfully

2. Dear Mr. Smith, Yours sincerely

First sentences, stating the purpose of the letter:

I am writing with regard to?

I am writing to request/ to ask for?

I am writing to thank you for?

I am writing to inform you that

I am writing to inform you of my decision to?

I am writing to complain about

I am writing to bring to your attention

On behalf of all of my?colleagues, I would like to thank you for?

Thank you for your help and support.

I look forward to receiving your response.?

I await your prompt response.

I hope that you will address these concerns as soon as possible. ( Complaint )

Please let me know if you require any further information.?

I hope that my request does not cause you any inconvenience.

Three tips:?

Avoid contractions: " I am " instead of "I'm"

Avoid direct questions: "I would like" instead of "Can I have?"

Avoid exclamation marks "!"