You need: a free account on ChatGPT, Claude or Gemini, a notes app, and a letter you need to write: to a landlord, a company, a school or an office. Cost: nothing.
Before you paste anything
Keep personal details out of the chat. The AI doesn't need your address, account numbers, ID numbers or anyone's phone number to write a good letter. Leave them out and type them in yourself at the end. Also check your assistant's Settings: unless you switch it off, your chats may be used to train its AI.
Step 1: Write your letter card (5 minutes)
Copy this into your notes app and fill in every bracket in ABOUT ME.
FORMAL LETTER CARD
You turn my rough notes into a polite, formal letter. I'll paste
my notes and who it's to. You write the letter. I check it, sign
it and send it.
ABOUT ME
- Sign-off name: [e.g. Sam Lee]
- My country: [e.g. Singapore] (for spelling and date style)
- My tone: [e.g. polite and firm, plain English]
WHEN I PASTE NOTES
1. If you can't tell who the letter is to, or what I want them
to do, ask me in one short message first.
2. Write one letter with:
A. A subject line.
B. One opening line on why I'm writing.
C. The facts, in date order.
D. Exactly what I'm asking for, and by when.
E. A polite close and my sign-off.
3. Put [brackets] wherever you need a detail I didn't give, such
as an address, a reference number or a date. Never fill these
in yourself.
4. Under the letter, add "CHECK:" and list every date, name and
promise in it, so I can confirm each one.
RULES
- Use only facts from my notes. Never invent dates, names,
reference numbers, laws or policies.
- Stay polite, even if my notes are angry. Firm is fine. Rude
or threatening is not.
- Don't admit fault or promise anything unless my notes say so.
- Under 250 words. Plain English, no legal-sounding filler.Step 2: Write your first letter (3 minutes)
Open a new chat. Paste your whole card, then your notes, typos and all. For example:
To: my landlord, Mr Tan.
"kitchen tap leaking since 12 Oct. texted him 14 Oct and 21 Oct,
no reply. now water damage in cupboard under sink. want a
plumber sent by end of next week. i think the lease says he
does repairs??"Read the letter and its CHECK list. The dates should be exactly 12, 14 and 21 October. "End of next week" should stay as you wrote it or become a [date] for you to fill in, never a date the AI picked. The lease point should appear in CHECK or be left out, never quoted as if the AI had read your lease. Add your details, then copy the letter into your email or a document.
Step 3: Test it (5 minutes)
Three quick tests show whether your card holds up:
- The thin-notes test: in a new chat, paste the card and just
Write to my bank about a wrong charge.It should ask what happened, or leave [brackets] for the date and details, not make them up. - The angry test: paste notes like "third time they've lost my order, this is a joke, I want them to sort it NOW." The letter should be calm and firm: the facts, then the ask. No insults and no threats.
- The change test: reply
Shorter, and a little less formal.It should rewrite the same letter and keep every fact.
If a test fails, don't start over. Add one rule to your card, such as "If my notes are unsure about something, put it under CHECK, not in the letter," and try again. Test, fix, retest: that's how a chat becomes a tool you trust.
Step 4: Keep it (2 minutes)
Your card is now a reusable tool. Next time, open a new chat, paste the card, then your notes. If your assistant can save instructions (a Project in ChatGPT or Claude, or a Gem in Gemini), you can paste the card in once instead. Menus change, but the card in your notes always works. Hit a limit? Paste your card into another assistant and carry on.
Bonus: a form instead of a letter
The same card helps with a form's free-text questions. Paste the questions as text, then your notes, and ask:
Draft a short answer to each question, in the same order, using
only my notes. Write ?? where my notes don't say.Type your personal details into the real form yourself.
Good habits
- Write the ask first in your notes. "Plumber by Friday" gives a sharper letter than a page of what went wrong.
- Read it aloud once. If a line sounds unlike you, change it. The letter goes out in your name.
- Keep a copy and note the day you sent it, in case you need to follow up.
What this doesn't do
On a free plan, the assistant only sees what you paste. It doesn't know your contract or the rules where you live, and it doesn't send anything. It isn't legal advice: for a serious dispute, talk to someone qualified. A fuller version, which drafts letters and emails and helps you fill in forms in plain language, is Tool 03 in Capstone AI Lab, the letter and form helper.