Thanks Adrian

This looks like the answer. I am assuming that the Application.Volatile
reference is switching this feature on for ALL udf's and can therefore be
placed in any startup code for the app.

Looking through some of the other posts relating to application.volatile it
appears that for Excel Services this can be declared using reflection for an
individual function. Are you aware of whether this technique could be used as
part of an automation add-in for use inside a normal Excel session?

"Adrian C" wrote:

Adrian C wrote:
Andrew Wiles wrote:

Is there any way to flag all udf's for re-evaluation?

Yes. Put "Application.Volatile" at the start of the UDF.


Oh, and then do Application.CalculateFull ...

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Adrian C