How to see what sheets/tabs are hidden in an Excel file

The Unhide dialog only shows you half the picture

Right-click any visible sheet tab and choose Unhide, and you'll get a list — but that list only includes sheets in the ordinary Hidden state. It's a genuinely incomplete inventory if the workbook also contains “very hidden” sheets, which don't appear in that dialog no matter how many hidden sheets it lists.

Why very-hidden sheets exist

Very hidden is a state that can only be set through VBA (setting a worksheet's Visible property to xlSheetVeryHidden rather than xlSheetHidden), and it's commonly used deliberately — to hide a calculation or lookup sheet that a workbook's formulas depend on, but that isn't meant to be casually unhidden by whoever opens the file. It's a real design pattern, not a corruption or an error, but it does mean the sheet is genuinely invisible to someone who only knows the normal right-click Unhide route.

How to reveal a very hidden sheet

Press Alt+F11 to open the VBA editor, find the sheet in the Project Explorer panel on the left (it will be listed even though it's very hidden), click it, and in the Properties panel below, change the Visible property from 2 - xlSheetVeryHidden to -1 - xlSheetVisible. If the VBA editor itself is disabled or the workbook is protected, you won't be able to do this from the Excel UI at all.

Checking without opening the VBA editor

A sheet's visibility state is stored as a plain attribute in the workbook's underlying XML, readable without running any macro or touching VBA at all. Upload your file below to see every sheet regardless of its visibility state — normal, hidden, or very hidden — listed together with its name and dimensions.