For lawyers: How to find hidden gems (or grenades) in spreadsheets

Key points

  • Parties exchanging spreadsheets in the context of litigation, transactions or other commercial dealings are often unaware of the extent of information they may be providing to, or receiving from, their counterparties.
  • This article explains how to check a number of areas for “hidden” information and, where appropriate, how to remove it.[1]
  •  Knowing about this enables parties exchanging spreadsheets to:

    (a) Avoid inappropriate disclosures;
    (b) Gain maximum information about the spreadsheets they receive;
    (c) Ask for other information sources that may be referred to in the spreadsheets they receive.

Where to find additional information

Microsoft Excel workbooks typically present numeric data in visible worksheets (shown as named ‘tabs’ at the bottom of the screen). However, sometimes there is more than meets the eye.

Workbooks often contain additional information in one or more of the following places:

  • File properties;
  • ‘Hidden’ worksheets;
  • ‘Very hidden’ worksheets;
  • Links to other workbooks;
  • Cell comments;
  • Macros.

However, there are other things about a workbook that you cannot uncover from reviewing the Excel file on its own.

File properties

File properties can provide insight into when a workbook was created (and by whom), last printed, last modified (and by whom) by clicking ‘File’ on the ribbon in Excel 2016. 

This information is also able to be removed in Windows Explorer by right-clicking the file, selecting ‘Properties’ and navigating to the ‘Details’ tab.

‘Hidden’ worksheets

Worksheets can be hidden in Excel workbooks, meaning the worksheet is unable to be seen when the workbook is opened. 

Worksheets can be unhidden by right-clicking on any worksheet tab and selecting ‘unhide’ or navigating to ‘Home’ > ‘Cells’ > ‘Format’ > ‘Hide & Unhide’ on the ribbon.

‘Very hidden’ worksheets

Unhiding sheets using the method described above will not reveal whether the workbook has any ‘very hidden’ sheets. 

These can only be viewed and un-hidden using the Microsoft Visual Basic Editor (VBE) (accessed by right-clicking a worksheet tab and clicking ‘View Code’ or using the keyboard shortcut “ALT + F11”). Worksheet visibility status can be changed in VBE between ‘visible’, ‘hidden’ and ‘very hidden’.

Links to other workbooks

Excel workbooks may contain links to other workbooks which have not been provided. Excel’s default security settings will provide a warning upon opening the file that ‘Automatic update of links has been disabled’ when a workbook has external links. 

Linked workbooks can be viewed by clicking ‘Edit Links’ in the ‘Data’ tab on the ribbon. Selecting ‘Break Link’ will replace all formulae that contain external links with the cells’ current values.

Cell comments

Cell comments can contain further information about the contents of a cell. A small red triangle in the top right corner of a cell indicates a cell comment, which will appear when the cursor hovers over the relevant cell. 

You can show/hide all comments in a worksheet from the ‘Review’ tab in the ribbon. Where a worksheet is large with numerous cell comments, it may be convenient to print all cell comments by selecting ‘Print Titles’ from the ‘Page Layout’ tab on the ribbon, then selecting ‘At end of sheet’ from the ‘Comments:’ drop-down box, and the printing the worksheet.


Excel workbooks often contain ‘macros’ (code written in VBE to automate certain processes, such as importing data from external sources or performing iterative calculations). Excel’s default security settings will provide a warning upon opening the file that ‘macros have been disabled’ when a workbook contains visual basic code.

Things you cannot uncover

 While the above techniques can uncover useful information, the following information is not able to be seen:

  • Version and edit history beyond created, last printed and last edited details (electronic document management systems may record further details); and
  • Mark-ups or tracked changes (a comparison of multiple versions of a file, if available, may enable an analysis of changes to be produced).


[1] Whilst procedures and screenshots in this article are based on Excel 2016, the steps are similar for previous versions of Excel.

How can we help?

Our forensic accounting and technology specialists are trained in the collection, analysis and presentation of evidence in the context of investigations and litigation and include advanced users of Microsoft Excel.

Please contact a Ferrier Hodgson partner in your nearest capital city if you would like assistance in understanding what sensitive information your electronic files may contain or an ‘Excel Basics for Lawyers’ training to be delivered to your team.