Count Number of Sheets in Workbook Based on Criteria in Sheet Name

Hello,

I have a workbook with multiple sheets - one for each client.
I also have a client list in the same workbook (lets say, starting in A1).
I want to add a column to the client list noting whether there's a sheet with that client name in the workbook (via COUNTIF then IF so that it returns "YES" or "NO")

Is this possible?

Thank you!

UPDATE: Just realized I could just use INDIRECT, based off the client name in the list, and have it return the value in cells "A1 of that sheet, then wrap it w/ IFERROR and IF statements to return a "NO" if it comes back as an error (i.e. no sheet with that name), and "YES" if it doesn't. This isn't the best solution (i.e. if there is a sheet but there happens to be an error in cell A1 of a client sheet, the formula would return a "NO". I don't plan on this happening, so I'll use this idea for now, but please feel free to let me know if there's a non "work around" answer to my original question.

Try this...

=IF(ISREF(INDIRECT("'"&A1&"'!A1")),"Yes","No")