English · Letter Writing
Formal and Informal Letter Format — The Difference
Both letter formats side by side, so you can tell at a glance which the question wants.
A formal letter carries the receiver's designation and address, the salutation "Sir" or "Madam", a subject line, and the subscription "Yours faithfully". An informal letter carries only your own address and the date, the salutation "Dear [name]", no subject line, and a warm closing such as "Yours ever". Everything else follows from which of the two the question asks for.
The format
Decide which one the question wants
Read the instruction before anything else. If the letter goes to a friend, a relative or a classmate it is informal. If it goes to an editor, a principal, an officer or a company it is formal. Everything else in the layout follows from that single decision, and getting it wrong costs marks in every part of the answer at once.
The two layouts side by side
What changes, part by part
| Part | Informal letter | Formal letter |
|---|---|---|
| Top of the page | your own address, top right | the receiver’s designation and address, left |
| Your address | at the top | at the end, under your name |
| Date | under your address | under the receiver’s address |
| Subject line | none | required — Subject: … |
| Salutation | Dear Rina, | Sir, / Madam, / Dear Sir, |
| Opening | a greeting | the purpose, stated at once |
| Register | contractions allowed, questions welcome | no contractions, no questions, no exclamations |
| Subscription | Yours ever / Yours affectionately | Yours faithfully / Yours sincerely |
| Signature | first name | full name |
Faithfully or sincerely
The two formal subscriptions are not interchangeable. Use Yours faithfully when the salutation is Sir or Dear Sir — that is, when you have not named the person. Use Yours sincerely when you have addressed them by name, as in Dear Mr Rahman. Boards test this pairing regularly and it is easy to get right.
- Sir, → Yours faithfully,
- Dear Sir, → Yours faithfully,
- Dear Mr Rahman, → Yours sincerely,
- Dear Rina, → Yours ever, / Yours affectionately,
What both formats share
Both need clear paragraphing with a blank line between paragraphs, a body organised so each paragraph does one job, and consistency of tense. Layout marks are given for what an examiner can see at a glance, so leave the spacing visible rather than filling the page.
Model answers
Informal skeleton
Green Road, Dhaka
5 September 2026
Dear Rina,
Opening paragraph — a greeting and the reason you are writing. One or two sentences is enough, and it is where an informal letter establishes that the two of you already know each other.
Middle paragraph — the subject of the letter, developed. This is where the content marks are, so it takes the most space: three or four sentences that say something specific rather than something general.
Closing paragraph — turn back to your reader. Ask after them or their family, invite a reply, and finish. A letter that never asks the reader anything reads as a speech.
Yours ever,
Sabbir
Formal skeleton
The Editor
The Daily Star
Kazi Nazrul Islam Avenue, Dhaka
5 September 2026
Subject: The matter, named in a few words
Sir,
First paragraph — state the purpose immediately. In a letter to an editor this is the request for space in the columns; in an application it is the post applied for or the permission sought. A formal letter does not warm up.
Second paragraph — the substance, with specifics: what the problem is, where, since when, and whom it affects. Facts belong here, and anything you cannot vouch for personally should be attributed rather than asserted.
Third paragraph — the request. Ask a named authority for a defined action, and stop. A formal letter closes at the request, with no good wishes after it.
Yours faithfully,
Md Sabbir Hossain
Rampura, Dhaka
What earns and loses marks
- 🚨 Decide formal or informal before you write a word — mixing the two layouts loses marks in the heading, the salutation and the subscription together.
- Never put the receiver’s address in an informal letter; it belongs on the envelope.
- Never put your own address at the top of a formal letter; it goes under your signature.
- Match the salutation to the subscription: Sir → faithfully, a name → sincerely, a friend → ever.
- Leave a visible blank line between paragraphs in both formats. Layout marks are awarded on appearance.
Mistakes to avoid
- ✗ Sir, … Yours sincerely, ✓ Sir, … Yours faithfully, — sincerely needs a named recipient
- ✗ Dear Rina, … Yours faithfully, ✓ Dear Rina, … Yours ever, — a formal subscription to a friend
- ✗ An informal letter with the friend’s address under your own. ✓ Only your own address, top right.
Frequently Asked Questions
Who is at the top of the page. An informal letter begins with your own address; a formal one begins with the receiver’s designation and address, and your address moves to the end. From that follow the differences in salutation, subject line, register and subscription — so identifying the type correctly settles most of the layout at once.
Use “Yours faithfully” when you have not named the person — after “Sir” or “Dear Sir”. Use “Yours sincerely” when you have named them, as after “Dear Mr Rahman”. Both are formal; the choice depends only on the salutation, which makes it one of the easiest marks in the paper to secure.
Yes, in the Bangladeshi board format. Write it after the date and before or just after the salutation, naming the matter in a few words. It takes five seconds and carries its own mark, so leaving it out is a straightforward loss.
In an informal letter, yes — “I’m” and “don’t” make it sound like a real letter to a friend. In a formal letter, no: write out “I am” and “do not”. Register is part of what the formal letter question is testing, and contractions are the clearest signal that it has slipped.
Keep going
Model answers, formats and grammar rules for every SSC and HSC writing question.