Attaching a Word, PDF or Excel file and asking the right questions

1Attaching is not enough, frame the question

Without a paid licence, Copilot Chat accesses neither OneDrive, nor SharePoint, nor your email. It reasons only on what you attach. Microsoft lists Word documents, Excel workbooks, PowerPoint presentations and PDFs, and spells out the uses: ask questions about the file, summarise it, run a data analysis. Upload is included, with so-called "standard" access, subject to service capacity at peak times.

The attached file is stored in your work OneDrive, you can delete it at any time, and it is not used to train the models. Limits on number and size exist, but Microsoft does not put figures on them; the values circulating (three files per day, 512 MB) come from forums and remain uncertain in September 2026.

Attaching is not enough. Your prompt must specify the exact processing required. Four disciplined habits make the output reliable. First, name the file and its role: "contract_2026.pdf contains the clauses to compare; ignore appendices". Second, restrict the source: "rely only on this attached file".

Third, demand exact quotations: "quote word for word the passage used and its location". Finally, plan for missing data: "if the information is not present, write not found". Without this last safeguard, the model fills gaps with plausible hallucinations.

Two precautions of form. One targeted file per prompt beats ten mixed documents: research shows that models make poorer use of information placed in the middle of a long context. And an Excel table is prepared before being attached: a single sheet, one header row, one row per record, no total row.

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2Two quotes compared criterion by criterion

A buyer has received two PDF quotes for renting ten laptops. Both files are attached.

Turn 1: Bounded comparison with missing data handling.

Compare the two attached quotes, quote_A.pdf and quote_B.pdf, on five criteria: total price excluding VAT, delivery time, payment terms, warranty, equipment take-back. Present a three-column table (criterion, quote A, quote B) and quote the passage from the quote for every cell. If a criterion does not appear in a quote, write "not found" instead of guessing. Rely only on these two files. Finish with three questions to ask the suppliers.

Summarised answer: a five-row table, two "not found" cells (delivery time for quote B, take-back for quote A), every amount accompanied by its exact quotation, and three focused questions on the gaps.

Turn 2: Commercial clarification follow-up.

To seek formal confirmation from supplier B immediately, the buyer follows up:

Draft an 80-word professional email for Supplier B, requesting written confirmation of their guaranteed delivery timeframe and hardware disposal terms.

Copilot generates a direct, courteous message ready to send via Outlook.

What changes.

The criteria are closed, making them directly comparable. Missing information is clearly exposed instead of being papered over with guesses. Every figure can be verified by opening the quote at the cited line.

3Make Copilot answer "not found"

To practice without wasting time drafting a fake document, here is a structured, anonymised staff handbook excerpt (fictional company NovaTech). You can copy this raw text or save it into a Word document handbook_sample.docx to attach it:

Staff Handbook Excerpt - NovaTech Ltd (Training Sample)
Article 1 - Hours and Attendance: Standard core hours are 9:00 AM to 6:00 PM with a mandatory one-hour lunch break.
Article 2 - Remote Work: Up to two days per week of remote work are permitted upon management approval following probation.
Article 3 - Special Leave for Family Events: Employees are entitled to 2 paid working days for moving house (upon submission of lease or deed, limited to once every two years). Parental leave at birth is 3 working days. (Note: no exceptional leave for weddings or civil partnerships is provided under this company agreement).
Article 4 - Data Protection: All internal information processing is subject to standard organizational security guidelines.

The "Load exercise" button in the composer pre-fills the objective with the weak starting prompt:

"What does this document say about leave?"

From this starting point, complete the prompt in the composer. Add the file name (handbook_sample.docx), restrict to this single source, require quotations with article numbers and the "not found" instruction.

Apply the end-instruction technique (arXiv:2307.03172) by placing the question and strict constraints at the very end, following the document reference. Then ask two questions: one about moving house, one about weddings. The second must come back "not found".

Self-assessment grid: (a) the file is named and the source restricted; (b) the quoted passage exists in your document, at the right article; (c) the trick question did produce "not found".

Open the prompt composer