Set it up properly

1. Draft your custom instructions

Custom instructions apply to every chat. Let ChatGPT draft them from a few facts, then you paste the result into Settings in the next step.

You are an expert at writing ChatGPT custom instructions for busy UK professionals.

About me:
- Role: {{role}}
- Organisation: {{organisation}}
- Who I usually write for: {{audience}}
- How I like answers: {{style}}

Task: write my custom instructions.

Constraints:
- Under 1,400 characters in total so they fit every plan.
- Always include: British English spelling, £, DD/MM/YYYY dates, UK law and terminology by default, answer first then detail, flag uncertainty, never invent statistics or sources, ask one clarifying question if my brief is ambiguous.
- Write in the second person ("You are helping...").

Output: two labelled blocks, "About me" and "How to respond", ready to paste, followed by the character count.

• Your role, for example: HR business partner
• Organisation and sector, for example: a 120-person housing association in Leeds
• Who you write for, for example: line managers and the senior leadership team
• How you like answers, for example: short, bullet points, plain English, no jargon

Where to paste: A new Chat conversation on Instant

What you should get: Two short blocks under 1,400 characters that mention British English, £ and UK law. Check that nothing in them is confidential, because custom instructions travel into every chat and some plugins.

Follow-ups

• Make the "How to respond" block 30% shorter without losing any rule.
• Add one line telling ChatGPT how to format emails for me.

2. Save the instructions

free, go: Free and Go are limited to 1,500 characters, so keep the draft from step 1 under that.

Paid plans can save 5,000 characters; Free and Go can save 1,500. Changes apply to all chats straight away.

1. Open Settings > Personalization Click your name or profile icon to find Settings. On mobile it is Settings > Customize ChatGPT.
2. Turn on Enable customization
3. Paste your text into the Custom Instructions field and save

3. Switch off training for work content

business, enterprise: Workspace content isn't used for training by default, and your admin may control memory settings.

On personal plans, Improve the model for everyone is on by default. Turning it off keeps your history. Business and Enterprise content isn't used for training by default.

1. Open Settings > Data controls
2. Select Improve the model for everyone, turn it off and select Done Giving a thumbs up or down can still send that conversation for training.
3. Open Settings > Personalization > Memory and review the Memory summary Correct anything wrong, or use Don't mention this again.

4. Tighten security and app permissions

App permissions decide when ChatGPT asks before reading or acting in a connected app. The default allows low-risk actions without asking.

1. Open Settings > Security and review Security history Check for sign-ins you don't recognise and set up multi-factor authentication or a passkey.
2. Open Settings > Plugins > Permissions and choose Always ask If you see Apps instead of Plugins, open Apps. The option appears once you have installed a plugin with an app.
3. Open Settings > Notifications and turn on Push or Email for tasks

5. Prove it worked

Start a brand-new chat and give ChatGPT almost no instructions. If your settings work, the reply should already sound like you.

Write a short email to {{recipient}} about {{topic}}.

• Who it's to, for example: a supplier who delivered late twice this month
• What it's about, for example: agreeing a firm delivery window from next week

Where to paste: A new Chat conversation on Instant, outside any project

What you should get: British spelling, the answer-first style you asked for and no invented facts. If it asks one clarifying question, that is your instructions working. If it sounds American or generic, edit your custom instructions and test again.

Follow-ups

• Make it firmer but still polite, and add a clear deadline of Friday.
• Which of my custom instructions did you apply in that email?

6. Know when to use Temporary chat

A temporary chat stays out of history, doesn't create memories and isn't used for training while it stays temporary. OpenAI may keep a copy for up to 30 days for safety.

1. Open a new chat and select Temporary
2. Choose Personalized or Unpersonalized before your first message You can't change it once the chat starts.
3. Confirm you can see the temporary chat label, then close it

Quick check

1. Where do you switch off training on a personal plan?

   • Settings > Personalization
   • Settings > Data controls > Improve the model for everyone (correct)
   • Settings > Security
   • The Privacy Center only

   Data controls holds the Improve the model for everyone switch.

2. What is true of a temporary chat?

   • It is never stored anywhere
   • It can be switched to personalised mid-chat
   • It may be kept for up to 30 days for safety (correct)
   • It creates memories

   Temporary chats skip history and training but may be kept for up to 30 days for safety.

3. Which app permission makes ChatGPT ask before reading or changing anything?

   • Allow read actions
   • Allow low-risk actions
   • Always ask (correct)
   • Allow all actions

   Always ask means ChatGPT asks before reading app information or making changes.