# Custom instructions (ChatGPT)

> A standing note about who you are and how you want ChatGPT to respond, applied to every chat unless a project says otherwise.

**Category:** ChatGPT

**Custom instructions are your permanent briefing for ChatGPT.** You write once who you are, what you do, and how you like answers (length, tone, format), and ChatGPT applies it to every new chat. Next to it, **Base style and tone** sets the overall personality.

They are broad by design. For one stream of work, use **project instructions** instead: inside a [project](/glossary#chatgpt-project) they take priority over your custom instructions. You find both under Settings, Personalization.

## At work

Add one line: "I work in Belgium, write in British English, and prefer short answers with the conclusion first." Every chat starts better.

## Often confused with

Memory. Custom instructions are what you tell ChatGPT on purpose; [memory](/glossary#chatgpt-memory) is what it picks up and saves along the way.

## Related terms

- Memory (ChatGPT)
- Project (ChatGPT)
- Context

## See it in a lesson

[Giving ChatGPT context](/en/learn/chatgpt/getting-started/giving-chatgpt-context)

## Further reading

- [Customizing your ChatGPT personality](https://help.openai.com/en/articles/11899719-customizing-your-chatgpt-personality): Custom instructions and base style.
- [Projects in ChatGPT](https://help.openai.com/en/articles/10169521-projects-in-chatgpt): Project instructions and how they take priority.
- [Memory in ChatGPT](https://help.openai.com/en/articles/8590148-memory-faq): The other way ChatGPT knows about you.

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Last updated: 14/10/2026  
Source: Rollo Academy glossary