Copilot in Word: summarise a document and reference a file

Two Copilot moves in Word solve a specific, common problem: reading something long quickly, and pulling one document's content into another without copy-pasting. Neither is complicated, but the second one — referencing a file — surprises people who don't know it exists.

Both live in the same place as every other Copilot feature in Word: the Copilot button on the ribbon, or the icon that opens a chat pane down the right side of the document.

Summarising a document

Open the document and ask Copilot to "summarise this document" — or select a section first and ask it to summarise just that. Copilot reads the whole thing (or the selection) and returns a short summary with the main points, which you can copy out, ask follow-up questions about, or use as the basis for an executive summary you paste into the document itself.

For a genuinely long document — a fifty-page proposal, a year of meeting minutes stitched into one file — a single "summarise this" prompt can get shallow. Asking section by section, or asking a more specific question ("what did we commit to in the pricing section?"), usually gets a sharper answer than a blanket summary request.

Referencing another file

This is the less obvious feature. Inside the Copilot pane, type @ and Word shows a picker of files you have access to — recent documents, files shared with you, anything on OneDrive or SharePoint that matches what you type. Pick one, and its content becomes context for whatever you ask next.

Practical uses:

• Draft from a source. "Using @[research notes], draft a one-page summary for the steering committee." Copilot reads the referenced file and writes the new content in the document that's currently open.
• Check consistency. "Does this contract match the terms in @[signed term sheet]?" — useful for catching a clause that drifted between drafts.
• Bring in a template's structure. Reference a previous report and ask Copilot to follow its section headings for a new one.

Referencing doesn't merge the files or change the referenced one. It's context for a prompt, not an import.

What it needs

A Microsoft 365 Copilot licence is required for both features; the free Copilot Chat experience doesn't run inside Word. Referencing a file only works if the signed-in account already has permission to open it — Copilot checks the same SharePoint and OneDrive permissions as everything else, so it won't surface a colleague's private draft just because you typed part of its name.

Where it falls short

Very long or heavily formatted documents (dense tables, tracked changes, embedded objects) summarise less cleanly than plain prose. Referenced files need to have finished syncing — a file just created or just shared can take a minute to become searchable. And Copilot reads text; a referenced file that's mostly scanned images or charts won't give it much to work with.

For related ground, Copilot in Word: draft from an outline and references covers building a document from scratch this way, and Copilot in Word: rewrite modes and coaching covers editing text that's already there.