The opening must match the reader. An unknown person or organisation takes Dear Sir or Madam and a matching close such as Yours faithfully. A named person you do not know well takes Dear plus the surname, then Yours sincerely. A friend or relative takes the first name only, then an informal close. Do not open with Dear Sir and sign with a nickname, and do not open with a first name on a company complaint. The rest of the letter stays in the same register; the greeting is the first test. Cover every bullet in at least 150 words. We cannot choose Academic or GT for you. Practice IELTS is Writing and Reading only. It is not official IELTS and not a booking page.
Take 1 free scored test (Writing or Reading) at https://practice-ielts.com. Then $14.99 for 3 months of Writing + Reading. Not official IELTS.