- Where ChatGPT earns its place in your writing
- Writing blocks: a draft you can edit inside the chat
- Set your tone once with custom instructions
- Characteristics: turn the emojis and markdown down
- Ask for the tone in plain words
- A simple routine for emails and updates
- What changes from plan to plan
- When your edits don't stick
- My verdict on ChatGPT for business writing
- Frequently asked questions
ChatGPT is useful for everyday business writing like client emails, team updates, social posts and short documents, and its own built-in tools do more of the work than most people realise. Writing blocks give you a draft you can edit right inside the chat, while custom instructions and characteristics let you set your tone once instead of repeating it in every prompt. As of Nov 2026, OpenAI's help pages say the actions you see vary by plan, device, workspace settings, model and rollout.
Most people type a request, copy the answer and fix it somewhere else. That ignores the settings OpenAI built for exactly this job, and the catches its own help pages list.
Where ChatGPT earns its place in your writing
The writing you repeat every week is where it pays off: the reply to a client who asked the same question as last month, the Friday update to your team, the scrappy notes that need to become a one-page document. These are short, structured and predictable, which is what ChatGPT handles well.
Writing blocks: a draft you can edit inside the chat
OpenAI describes writing blocks as "editable areas for draft text, such as emails, messages, social posts, and documents." When ChatGPT creates text you're likely to revise or reuse, it may put the draft in a writing block on its own. You can also ask for one directly.
Depending on the block and the actions available to you, you can:
- Select the block and edit the text yourself.
- Copy the text.
- Ask ChatGPT to revise only the text you've selected, or the whole draft.
- Open the block in a full-screen editing view.
- Undo or redo recent AI-assisted edits.
- Send supported email drafts straight from ChatGPT where that's available, or open them in your email app.
- Save supported document drafts to your Library, where available.
Writing blocks also handle the formatting a business document needs: bold and italic text, headings, links, bulleted and numbered lists, and checklists.
The catch nobody mentions: you may not see every action in every conversation. OpenAI says it depends on the type of block, your device, your plan, your workspace settings and whether the feature is switched on for your account. So if a colleague has a send button and you don't, nothing's broken. You're just on a different setup.
Three starter prompts from OpenAI's own help page
Draft a reply email to my manager.
Write a short Slack update for my team.
Turn these notes into a one-page document.
Set your tone once with custom instructions
Custom instructions let you share anything you'd like ChatGPT to consider when it responds, and they're applied straight away to all your chats. As of Nov 2026 they're available on every plan, on web, desktop, iOS and Android. On web and desktop you'll find them under Settings, then Personalization, where Enable customization needs to be switched on. On iOS and Android, go to Settings, then Customize ChatGPT.
For writing, this is where you put the things you're tired of repeating: who your readers are, how formal you want to sound, the words you never use and how you sign off. If you'd like to see what other people put in theirs, I've collected examples of custom instructions separately.
Two details are worth knowing. First, the space you get depends on your plan. As of Nov 2026, Free and Go users can save up to 1,500 characters, while Plus, Pro, Enterprise, Business and Education users can save up to 5,000 characters. Second, changes only apply to future conversations. Old chats keep the version you had at the time, and the only way to remove instructions from those is to clear the conversations from your history.
One honest line from OpenAI's page: it says information from your use of custom instructions will also be used to improve model performance. If that matters to you, look at ChatGPT's data controls in Settings before you write anything sensitive into them. Your instructions aren't shared with people who view a shared link.
Characteristics: turn the emojis and markdown down
Characteristics adjust the feel of ChatGPT's replies across chats without changing what it can do. There are four: Warm, Enthusiastic, Headers and Lists, and Emojis. Each one can be nudged in a more direction or a less direction, and they work alongside your chosen personality, your custom instructions and any saved memories. Once set, ChatGPT tries to follow that style in the current chat and in new ones.
For business writing, the less settings are the useful ones:
- Warm, less: keeps the same length and completeness but uses a more emotionally neutral tone.
- Headers and Lists, less: called Use less markdown, it uses fewer formatting elements and relies more on paragraphs.
- Emojis, less: called Use fewer emojis, it uses them sparingly in chatty replies and not at all in informational ones.
On web, select your profile icon at the bottom right and open Personalization. On iOS and Android, select your profile icon in the sidebar, then Personalization, then Characteristics. An email full of headings and bullet points reads like a report. Paragraphs read like a person wrote them.
| Setting | What it controls | Where or when it applies |
|---|---|---|
| Writing blocks | An editable draft for emails, messages, posts and documents | Inside the chat, either automatically or when you ask |
| Custom instructions | What ChatGPT considers in every reply | Settings, Personalization (web and desktop); Settings, Customize ChatGPT (mobile) |
| Characteristics | Warmth, enthusiasm, headers and lists, emojis | Profile icon, Personalization |
| Temporary Chat | A conversation where block edits may not persist | Only that chat; edits may be gone once it ends |
Ask for the tone in plain words
OpenAI's own prompt guide is refreshingly short. Be clear and specific, give enough context for ChatGPT to understand what you're asking, and avoid ambiguity. Then iterate: start with a first prompt, review what comes back and refine it by adjusting the wording, adding context or simplifying the request.
For tone, the guide suggests descriptive adjectives such as formal, informal, friendly, professional, humorous or serious, with the example "Explain this in a friendly and engaging tone." That's it. You don't need a twelve-part formula. Two adjectives and a clear job usually get you closer than a paragraph of rules.
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A tone prompt to adapt
Rewrite this reply to a client in a friendly, professional tone. Keep it short and keep my sign-off.
If you want more speed than tone, I've written about using ChatGPT to write faster, and for social posts there's a set of LinkedIn prompts that sound like you.
A simple routine for emails and updates
- Set custom instructions once: who you write for, how you sign off, and the words you don't want to see.
- Open Characteristics and turn Headers and Lists and Emojis down, so drafts arrive as plain paragraphs.
- Ask for the draft in a writing block and paste your rough notes in with the request.
- Select the sentence that feels off and ask ChatGPT to revise only that part. Undo if it gets worse.
- If the whole draft still sounds wrong, ask again with one or two tone adjectives.
- Copy it out, send a supported email draft from ChatGPT where that's offered, or save a document draft to your Library.
What changes from plan to plan
The biggest plan difference for writers is the custom instructions limit: 1,500 characters on Free and Go, 5,000 on the paid and workspace plans, as of Nov 2026. Sending email drafts from ChatGPT and saving to your Library are both marked "when available", so don't build a team process around them until you've seen the buttons on your own account. Check the vendor's own page for the current price of each plan.
For anything longer than an email or a one-page document, Canvas is the better place to work, and I've explained ChatGPT Canvas for longer documents on its own page.
When your edits don't stick
Edits to supported writing blocks save with the conversation after a short delay, and ChatGPT can then use your latest version when you ask a follow-up. So give it a moment after a big edit before you ask for the next change, or you may get a revision of the old text.
Temporary Chat is the bigger trap. OpenAI says edits there may not persist after the conversation ends. If you've polished a draft in a Temporary Chat, copy it somewhere safe before you close the window. And if you've just changed your custom instructions, start a new chat to see them work, because existing conversations won't pick them up.
My verdict on ChatGPT for business writing
I'd set custom instructions and turn the emojis and markdown down once, skip fancy prompt formulas, and always rewrite the first and last lines myself. These settings shape tone and layout. They don't make ChatGPT sound like you, and the people who read your emails know your voice better than any setting does.
Features and limits change often, so as of Nov 2026 treat everything here as a snapshot and check OpenAI's own help pages for the latest.
If your team writes a lot and wants AI help that still sounds like each of you, that's the kind of AI enablement I help with. I run AI training and workshops for teams, and help businesses with AI enablement and workflow automation, so the busywork runs itself and people get time back. Most of that work is with SaaS marketing teams and small businesses. Here's how we can work together.
Frequently asked questions
Is ChatGPT good for writing emails?
Yes, for short, repeatable emails it's a good first-draft tool. Ask for the draft in a writing block, edit it in the chat, then rewrite the opening and the ask yourself.
What are writing blocks in ChatGPT?
OpenAI describes them as editable areas for draft text such as emails, messages, social posts and documents. You can edit the text directly, ask ChatGPT to revise a selected part, and undo AI-assisted edits.
How long can ChatGPT custom instructions be?
As of Nov 2026, Free and Go users can save up to 1,500 characters, and Plus, Pro, Enterprise, Business and Education users up to 5,000 characters.
Why didn't my edits to a ChatGPT draft save?
Edits save with the conversation after a short delay. In Temporary Chat, OpenAI says edits may not persist after the conversation ends, so copy the draft out first.
How do I stop ChatGPT using so many emojis and bullet points?
Open Personalization, then Characteristics, and set Emojis and Headers and Lists to less. That uses fewer emojis and relies more on paragraphs.
