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 FileMaker Pro Custom Functions

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IsValidBankNumber ( banknummer )

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  Average rating: 3.9  (35 votes)
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Theo Ros, *

Checks a Dutch banknumber for validity.

Sample Input:
IsValidBankNumber ( "123456789" )
Sample Output:

 Then copy & paste into FileMaker Advanced's Edit Custom Function window.


Returns "true" if banknummer passes the '11-proef',
"false" if not or an empty string if banknummer is empty.

Note: these functions are not guaranteed or supported by Please contact the individual developer with any questions or problems.

This is my Custom Function and I want to edit it


Bank ING has a serie of bankaccounts that does not follow your algoritm. Those are the former 'Postbank' accounts.
Is there a way to check those too?

Thibaud, Amstelveen, NL
April 15, 2012 2:45am

for Postbank numbers there is no validity check. The only thing you could do with those is that the numeric value must be less than 100.000.000 (100 million).

Only ING (Postbank) can check if it is a valid, issued number..

Theo Ros, Hilversum
April 15, 2012 4:09am

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