From Excel Help:
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Feature Maximum limit
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Cell styles in a workbook 4,000
Custom number formats Limited by available memory

From a convenience standpoint, I would declare a style for the custom
format, then apply the style to all cells in the workbook that use that same
format. Styles are a much easier way to build templates, as you have more
confidence that the cell will have the desired appearance when data is
eventually entered.

To add the Style control to the Formatting toolbar, right click on any
toolbar, choose Customize, then select the Commands tab. Select Format in
the Categories list box on the left, then drag the Style control from the
list box on the right to your Formatting toolbar.

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Regards,
Bill


"snels" wrote in message
...
Is there a limit on how many times a custom format can be used?