Quick answer
An informal letter is a personal letter written to someone you know well — family, friends, or people you're close to — and it follows a loose, conversational structure rather than a rigid business format. It still has a recognisable shape (date, greeting, opening, body, closing, sign-off), but every part of it is allowed to sound like natural speech, contractions and all.
What are the parts of an informal letter?
An informal letter is built from six parts, in this order:
- Date. Write the date at the top, on its own line. A full or short format both work — "14 August 2026" or "14/08/26".
- Greeting. Use the person's first name only, with a casual opener: "Dear Ada," "Hi Ada," or "Hello Ada,". No surname, no title, no "Dear Sir/Madam".
- Opening line. A short, warm line that gets the letter moving — apologise for the silence, react to their last letter, or simply say how good it is to write to them.
- Body paragraphs. One or more paragraphs sharing your actual news, questions, or reason for writing. This is the longest part and can move between topics naturally, the way a conversation would.
- Closing line. A line that wraps up and invites a reply — "Write back soon," "Looking forward to hearing from you," or "Can't wait to see you."
- Sign-off and name. A casual sign-off such as "Take care," "Lots of love," or "Your friend," followed by your first name only.
That's the full skeleton. There's no fixed word count and no requirement to include a return address, though some people still add a small address line in the top corner out of habit — it isn't required the way it is in a formal letter.
How does the tone differ from a formal letter?
The difference between a formal and an informal letter isn't really about structure — it's about tone and word choice. A formal letter (a job application, a complaint to a company, a letter to an official) is polite, precise, and emotionally neutral: it uses full names, titles, and closings like "Yours sincerely" or "Yours faithfully," and it avoids contractions and slang. An informal letter does the opposite on every count:
- Language: everyday words and contractions ("I'm", "we've", "can't") instead of formal phrasing.
- Address: first name only, never a surname or title like "Mr." or "Mrs."
- Emotion: informal letters are allowed to be warm, funny, or emotionally expressive — a formal letter deliberately isn't.
- Structure: a formal letter follows strict paragraph rules; an informal letter can move between topics the way a real conversation does.
A useful test: if you'd say it out loud to the person over a phone call, it probably belongs in an informal letter. If you'd only ever say it in a meeting, it belongs in a formal one.
Sample letter
Here is a complete informal letter from one friend to another, catching up after a while apart. Copy it and swap in your own details.
14 August 2026 Dear Chioma, I hope this letter meets you well o! I know it's been a while since we last spoke properly, and I'm sorry it took me this long to write back — Lagos has had me running around since the new job started. Speaking of which, work has been good. The new role at [Company Name] is busier than I expected, but I'm learning a lot, and my team is friendly enough that it doesn't feel like a strange place anymore. How is everything with you in [City/Town]? Last I heard, you were thinking of starting that small business — did you go ahead with it? I want to hear every detail, so don't leave anything out when you write back. Things at home are fine. Mum asks about you every time I call her, and I told her you'd probably visit before the end of the year — please don't make me a liar! My younger brother just gained admission to study [Course] at [University], so the house has been in celebration mode for about two weeks now. I was also thinking — it's been too long since we sat down together properly. If you're free sometime in [Month], maybe we can plan a weekend to catch up in person? Let me know what works for you. Write back soon and tell me everything I've missed. Take care of yourself, and greet your family for me. Lots of love, Amaka
What greeting and closing should you use?
Because an informal letter is written to someone you already know, the right greeting and closing depend entirely on the relationship — there's no single correct answer, only options that fit the tone:
- Greetings: "Dear [Name]," is safe for almost any relationship; "Hi [Name]," or "Hello [Name]," feel a touch more casual and suit a closer friendship.
- Closings: "Take care," and "Best wishes," work broadly; "Lots of love," "Your friend," or "Missing you," suit family and close friends specifically.
Whatever you pick, keep the greeting and closing in the same register — pairing a very casual "Hi" with a stiff "Yours sincerely" reads oddly, because it mixes formal and informal conventions in one letter.
People also ask
What are the six parts of an informal letter?
Date, a first-name greeting, an opening line, body paragraphs, a friendly closing line, and a sign-off with your first name — no address block or subject line needed.
How do you start an informal letter?
With the date, then a warm first-name greeting such as "Dear Ada," or "Hi Ada," followed by a friendly opening line before you move into your main news.
How do you end an informal letter?
With a line inviting a reply, such as "Write back soon," then a casual sign-off like "Take care," or "Lots of love," followed by your first name only.
Can you use contractions in an informal letter?
Yes — contractions like "I'm" and "can't" are expected in an informal letter, since the whole point is a natural, conversational tone.