Copilot Custom Instructions: 12 Examples for Work
The short answer: custom instructions are the standing rules Copilot follows in every chat. Format, tone, language, what to always include. Set them once under Settings and more, then Chat settings, Personalization, Custom instructions. Keep them short and specific.
Below: the exact path, how they differ from Copilot Memory, and 12 examples you can copy and adapt, from general rules to role-specific ones.
Where to set Copilot custom instructions
1Open the settings
At the top right of the Copilot app, select ... Settings and more, then Chat settings.
2Go to Personalization
Select Personalization from the left-side menu and find the Custom instructions tile.
3Write and save
Select Edit instructions, write your rules, then Save instructions. To pause them, move the Custom instructions toggle to Off.
Custom instructions vs Copilot Memory
These 2 sound alike. Microsoft's own distinction is simple. Custom instructions are what you explicitly tell Copilot about how to behave, like keeping emails concise. Memory is what Copilot picks up from your conversations, like the project you're working on.
1Memory is on by default
And it only saves something when there's a clear intent to remember. Microsoft's example: Copilot, remember that I prefer Excel over PowerPoint for reporting.
2Ask what it knows
Type What do you know about me and read the answer. Very educational. Sometimes a little awkward.
3Off is not deleted
Turning off Copilot Memory doesn't delete memories it already saved. Use Manage saved memories and delete them separately.
4Temporary chat
Start a temporary chat to work without using or updating memory. Your organisation's retention policy may still keep that chat.
Microsoft lists 4 ways Copilot personalises answers: saved memories, inferences from your chat history, insights from your work content, and your custom instructions. Memory works for Copilot Chat users with and without the paid licence. Microsoft Learn still labels personalisation and memory as preview, so expect changes.
How to write instructions that actually stick
Microsoft's example is refreshingly boring: When summarizing a meeting, use bullet points for key details instead of paragraphs. One situation, one behaviour. That's the pattern.
2 more rules from Microsoft's prompting guidance apply here too. Tell Copilot what to do rather than what not to do, and use if-then instructions. And for its Cowork feature, Microsoft warns that long or conflicting instructions leave less room for the task and affect response quality. I'd apply that everywhere.
6 general examples for anyone at work
Start every answer with the bottom line in 1 or 2 sentences, then the details.
Write in British English, use metric units and euros, and format dates as 28 September 2026.
When I ask you to compare options, answer with a table and end with your recommendation.
When you draft an email, keep it under 120 words, friendly and direct, with the request in the first line.
If my request is unclear, ask me up to 2 questions before you answer.
When you use my files or emails, name the source after each key fact.
6 examples by role
I manage a team of 8. When I ask for feedback or reviews, stick to observable work and examples, and leave ratings to me.
I sell B2B software in the DACH region. When I prep for a client, list their recent news, our last 3 interactions, and 3 questions to ask.
When you work with numbers, show the calculation, round to 2 decimals, and flag any figure you couldn't verify.
Write in gender-neutral language. When a request touches pay, performance or dismissal, remind me to check it with HR policy.
I work in English and German. Answer in the language I write in, and when you translate, keep product names and job titles in English.
When I ask for a status update, use 3 headings: done, next, blocked. Put owners and dates next to each item.
Team working across languages? See Copilot training for multilingual teams.
What to check, and where else instructions live
1Test after saving
Run a normal task, like summarising an email thread, and see if the format changed. If not, make the rule shorter and more specific.
2Notebooks have their own
Each Copilot Notebook can carry its own instructions, which is perfect for a single client or project.
3Cowork has its own too
Copilot Cowork has separate custom instructions under Customize, on the Preferences tab, with a documented limit of 20 KB (about 3,000 English words). That limit doesn't apply to Copilot Chat.
Once your instructions are in place, scheduled prompts are the next habit worth building. And for prompts by app, there's my Microsoft 365 Copilot prompt library.
Questions about Copilot custom instructions
Where are custom instructions in Microsoft Copilot?
At the top right of the Copilot app, select Settings and more, then Chat settings. Choose Personalization, find the Custom instructions tile, select Edit instructions, and then Save instructions.
What is the character limit for Copilot custom instructions?
Microsoft doesn't publish one for Copilot Chat. Copilot Cowork, a separate feature, documents a limit of 20 KB, about 3,000 English words.
What's the difference between Copilot memory and custom instructions?
Custom instructions are rules you set explicitly, like keeping emails concise. Memory is what Copilot picks up from your conversations when there's a clear intent to remember, like the project you're working on.
How do I turn off Copilot custom instructions?
Move the Custom instructions toggle to Off in the Personalization settings.
Does turning off Copilot Memory delete what it remembers?
No. Turning off Copilot Memory doesn't automatically delete memories it already saved. You delete them separately from Manage saved memories.
Want your whole team set up in one session?
I run live online Copilot workshops for groups of up to 20 people, from 1.5 to 4 hours. Custom instructions are the first setting I'd get everyone to save.