Letter Writing: Formal and Informal Formats (With Examples)
How to write formal and informal letters in English: the correct format, greetings and sign-offs, sample letters, and the mistakes to avoid.
Letter writing is the skill of putting a clear message into a fixed format so the reader knows who wrote, why, and what response is needed. In India it matters twice over: it carries marks in school and competitive exams, and it runs daily office work like leave, complaints, and requests. There are two broad kinds, formal letters for offices, editors, and officials, and informal letters for family and friends. This page gives you the formats, a full worked sample of each, and copy-paste exam templates you can adapt today. For guided practice, see our English writing classes and writing skills pages.
What letter writing is and its main types
Letter writing is composing a written message in a set structure so it reaches a specific reader with a clear purpose. Every letter names a sender, a receiver, a reason, and usually a request or reply expected. The format is what separates a letter from a random note.
There are two main types you will meet in Indian schools, exams, and workplaces.
- Formal letters: written to people you address by post or designation, not by first name. Examples include a leave application, a complaint to a company, a letter to the editor, or a letter to your principal or an officer.
- Informal letters: written to family and friends. The tone is warm and personal, like a letter to your mother, a friend, or a cousin.
Strong letters also build on good sentence habits. If tone and word choice trip you up, our vocabulary and business English vocabulary pages help you pick the right register.
Formal vs informal letters: a side-by-side comparison
The quickest way to choose a format is to compare the two side by side. A formal letter follows a strict layout and a neutral tone, while an informal letter is looser and personal.
| Feature | Formal letter | Informal letter |
|---|---|---|
| Reader | Officer, company, editor, principal | Family or friend |
| Sender address | Yes, top left | Yes, top left |
| Receiver address | Yes, below date | No |
| Subject line | Yes, one line | No |
| Salutation | Dear Sir / Madam, Dear Mr Rao | Dear Ravi, Dear Amma |
| Tone | Neutral, polite, direct | Warm, chatty, personal |
| Contractions | Avoid (do not, I am) | Fine (don’t, I’m) |
| Length | Short and to the point | Can ramble a little |
| Closing | Yours faithfully / sincerely | Yours lovingly, With love |
| Signature | Full name below closing | First name only |
Formal letter format, part by part
A formal letter has eight parts, each in a fixed position. Learn the order once and it works for every formal letter you write.
1. Sender’s address
Your own address goes at the top left, three or four lines, no name inside it. This tells the reader where to reply.
2. Date
Write the date below your address. In India the common form is 18 July 2026 or 18/07/2026. Keep one style through the letter.
3. Receiver’s address
Below the date, add the designation and address of the person you are writing to, for example The Manager, then the company name and address.
4. Subject line
One short line that states the purpose, for example Subject: Application for three days of leave. The reader should grasp the point before reading the body.
5. Salutation
Use Dear Sir or Dear Madam when you do not know the name, or Dear Mr Sharma when you do. Put a comma after it.
6. Body
Three short paragraphs work best. The first states why you are writing, the second gives the detail or reason, and the third states the exact action you want and thanks the reader.
7. Complimentary close
Write Yours faithfully (name unknown) or Yours sincerely (name known), aligned with the rest of the letter.
8. Signature and name
Sign, then print your full name below, and your designation or class if relevant.
| Part | What goes here | Example |
|---|---|---|
| Sender address | Your address, no name | 42 MG Road, Pune 411001 |
| Date | Day month year | 18 July 2026 |
| Receiver address | Designation and address | The Manager, HDFC Bank, Pune |
| Subject | One-line purpose | Subject: Request to reissue passbook |
| Salutation | Dear Sir / Madam, | Dear Sir, |
| Body | Purpose, detail, request | Three short paragraphs |
| Close | Yours faithfully / sincerely | Yours faithfully, |
| Signature | Sign and print name | Anjali Verma |
Informal letter format
An informal letter is shorter on structure and longer on warmth. You still keep your address, the date, and a greeting, but you drop the receiver’s address and the subject line.
- Sender’s address and date at the top left.
- Salutation using the person’s name or relation, for example Dear Rohan or Dear Nani.
- Body in an easy, chatty tone: greet them, share your news, ask about theirs.
- Closing such as Yours lovingly, With love, or Your friend, followed by your first name.
Even a friendly letter reads better with clean grammar. Brush up on the basics on our grammar page.
Block style vs indented style
These are two ways to lay a letter on the page. Block style aligns everything to the left with no paragraph indents, while indented style indents the first line of each paragraph and staggers the address lines.
| Point | Block style | Indented style |
|---|---|---|
| Alignment | All flush left | Address lines staggered |
| Paragraphs | No indent, blank line between | First line indented |
| Look | Modern, office standard | Traditional, common in exams |
| Best for | Emails, business letters | School exam answers |
Step by step: how to write a formal letter
Write a formal letter in seven steps, top to bottom, and you will not miss a part.
- Step 1: Put your address top left, then the date below it.
- Step 2: Add the receiver’s designation and address.
- Step 3: Write a one-line subject that states your purpose.
- Step 4: Choose the salutation, Dear Sir/Madam or the name.
- Step 5: Write the body in three short paragraphs: why, detail, request.
- Step 6: Close with Yours faithfully or Yours sincerely.
- Step 7: Sign and print your full name below.
Workplace letters and emails follow the same logic. Our business English page covers office tone in more depth.
A full sample formal letter
Here is a complete formal letter you can study and copy the shape of. It is a complaint about a faulty product.
27 Lake View Apartments,
Anna Nagar, Chennai 600040
18 July 2026
The Customer Care Manager,
BrightHome Appliances,
Mount Road, Chennai 600002
Subject: Complaint about a defective mixer grinder (Order 48213)
Dear Sir,
I am writing to report a fault in the mixer grinder I bought from your store on 5 July 2026. The motor stops within a minute of use and gives off a burning smell.
I have used it only three times, and the warranty card is still valid. The bill number is 48213 and the model is BH-750. I have kept the box and all the accessories safe.
Please arrange a replacement or a full refund within seven working days. I have attached a copy of the bill. Thank you for your prompt attention.
Yours faithfully,
Meera Krishnan
A full sample informal letter
Here is a complete informal letter to a friend, showing the warmer tone and looser structure.
14 Green Park,
Lucknow 226001
18 July 2026
Dear Aditya,
How are you? I hope your new college is treating you well and that Lucknow’s summer is not troubling you too much. I have been meaning to write for weeks.
I have great news. I finally cleared my driving test, and Papa has promised a short road trip to Nainital in September. You must join us. It would be just like our school holidays, only with better snacks this time.
Do write back soon and tell me your dates. Give my regards to your parents.
Yours lovingly,
Rhea
India and exam templates you can copy and paste
These four templates cover the letters Indian learners search for most. Swap the bracketed parts for your own details.
1. Leave application to your employer
Subject: Application for [three] days of leave
Dear Sir/Madam,
I request leave from [start date] to [end date] as [reason, e.g. I have a family function out of town]. I have handed over my pending work to [colleague’s name]. Kindly approve my leave. Thank you.
Yours faithfully, [Your name]
2. Complaint letter (to a company or authority)
Subject: Complaint regarding [the problem]
Dear Sir,
I wish to bring to your notice that [describe the problem clearly, with date and place]. This has caused [the effect]. I request you to [the exact action you want] within [time frame]. I have attached [any proof]. Thank you.
Yours faithfully, [Your name]
3. Letter to the editor
Subject: [The public issue, e.g. Overflowing garbage in Sector 12]
Sir,
Through your esteemed newspaper, I wish to draw the attention of the authorities to [the issue and where it happens]. [One or two sentences on why it matters to residents.] I request the concerned department to [the action needed] at the earliest. I hope you will publish this letter.
Yours faithfully, [Your name and city]
4. Letter to the principal (leave or request)
Subject: Application for [leave / fee concession / bonafide certificate]
Respected Sir/Madam,
I am a student of Class [X], Section [Y]. I request [state your request clearly, with dates and reason]. Kindly grant me [what you need]. I shall be grateful.
Yours obediently, [Your name, class and roll number]
| Template | Salutation | Common close |
|---|---|---|
| Leave to employer | Dear Sir/Madam, | Yours faithfully |
| Complaint | Dear Sir, | Yours faithfully |
| Letter to editor | Sir, | Yours faithfully |
| Letter to principal | Respected Sir/Madam, | Yours obediently |
How to address an envelope
Write the receiver’s full name and address in the centre of the envelope, and your own return address smaller in the top left corner. The PIN code goes on its own, clearly, so sorting machines read it correctly.
- Line 1: Name or designation, for example Mr Suresh Rao or The Principal.
- Line 2: House number and street or building.
- Line 3: Locality or area.
- Line 4: City and PIN code, for example Jaipur 302001.
- Return address: your own address, smaller, top left.
Letter writing mistakes to avoid
Most lost marks and weak letters come from a short list of repeat errors. Fix these and your letters jump a level.
- Mixing formal and informal tone, for example Dear Sir with Hey there.
- Forgetting the subject line in a formal letter.
- Closing wrongly: Yours faithfully after using the person’s name, or the reverse.
- Long, winding sentences instead of three tight paragraphs.
- Overused Indian-English phrases like do the needful, revert back, and kindly intimate.
- Missing the PIN code or the date.
- Writing a whole page when four sentences would do.
The fastest fix is feedback on your own writing. A tutor who marks your actual letters, not a generic template, catches the habits you cannot see. That is the core of our 1-on-1 writing classes, where you get full attention instead of the shared, scattered time of a group room.
Get your own letters marked, not just a template to copy
Free formats get you started, but a letter improves only when a tutor reads your own work and shows you exactly what to fix. In a group class your writing is rarely marked and speaking time is shared, so mistakes repeat. Our dedicated 1-on-1 sessions give full attention to your weak areas, from tone to punctuation. Try a ₹299 demo, a level assessment where you also see how online 1-on-1 classes work.
Book a ₹299 Demo ClassFrequently Asked Questions
What is the difference between a formal and informal letter?
A formal letter goes to an office, an official, an editor, or an institution, and it follows a strict layout with a subject line, a neutral tone, and a fixed closing. An informal letter goes to family or friends and is warm, chatty, and personal, with no receiver address or subject line. Formal letters avoid contractions like don’t, while informal ones use them freely. In short, the reader decides the type, and the type decides the format and tone.
What is the format of a formal letter?
A formal letter has eight parts in a fixed order: your sender address, the date, the receiver’s address, a one-line subject, the salutation, the body, the complimentary close, and your signature with printed name. The body works best in three short paragraphs that state the purpose, give the detail, and make the exact request. Keep the tone polite and direct, and match the close to the salutation. This same format covers applications, complaints, and official requests.
How do I start and end a formal letter?
Start with Dear Sir or Dear Madam if you do not know the name, or Dear Mr Sharma if you do, followed by a comma. Open the body by stating your purpose in the first sentence, for example I am writing to request or I wish to complain about. End with Yours faithfully when you did not use a name, or Yours sincerely when you did. Then sign and print your full name below.
How do I write an informal letter to a friend?
Put your address and the date at the top left, then greet your friend by name, such as Dear Rohan. Open by asking how they are, share your news in an easy, natural tone, and ask about theirs. Contractions like I’m and we’ll are fine and make it sound real. Close with Yours lovingly, With love, or Your friend, and sign with your first name.
What salutation should I use for a formal letter?
Use Dear Sir or Dear Madam when you do not know the reader’s name, and Dear Mr Rao or Dear Ms Iyer when you do. For a letter to the editor, Sir is the traditional opening. For a letter to your principal, use Respected Sir or Respected Madam. Always put a comma after the salutation and remember that the salutation sets which closing you must use.
How do I address an envelope in India?
Write the receiver’s name or designation, house number and street, locality, and then the city with the six-digit PIN code, centred on the envelope. Put your own return address, smaller, in the top left corner. The PIN code is the most important part because Indian post sorts by it first. A missing house number or PIN is the top reason letters get delayed or returned.
Which is better for exams, block style or indented style?
Both are accepted by most Indian boards, so pick the one you write most neatly and keep it consistent through the whole letter. Block style keeps every line flush left with a blank line between paragraphs and looks modern. Indented style staggers the address lines and indents the first line of each paragraph, which many students find familiar. The marks come from correct parts and clean layout, not from which style you choose.
How long should a formal letter be?
A formal letter should be short, usually three tight body paragraphs that state the purpose, the detail, and the request. Anything longer risks burying the point and losing the reader’s patience. Aim to say everything a busy officer needs in under 150 words of body text. If you find yourself repeating a point, cut it, because clarity, not length, is what gets a formal letter acted on.
Related Writing Lessons
Writing Skills Guide
All free writing lessons.
WritingEmail Writing
Write clear, professional emails.
ExamsIELTS Writing Task 1
General letter task.
CourseEnglish Writing Classes
1-on-1 writing coaching with feedback.
WritingParagraph Writing
Build clear paragraphs.
CourseBusiness English
Workplace writing and speaking.