Business letters should have Open Punctuation in the address, salutation and closing. Closed punctuation should only be used in the body of the letter.
Open punctuation Means no full stops, commas or any punctuation.
Closed punctuation Means using appropriate punctuation such as full stops and commas.
Justification Generally, left justification is used in most business letters, some business prefer to use the block justification for the body of the letter.
The letterhead usually contains a business logo, address and contact details, this can be set out in a variety of ways.
The inside address, date and greeting and signature block are left justified
The body is either left justified or block.
Date This is written in full: 28 October 2010 Notice there is no 'th' and the month is written in full not abbreviated to words or numbers.