RE: How to (dis)able duplicate check on Tax Exempt Numbers (VATs) in Dynamics 365 F&O?
You can disable the validation with extensions, by making the method always return true. However you would still see the warning infolog. To get rid of that, you would need to add bit more code, suppressing the infolog for the duration of the method. Also, I don't know if this would break some local legislation, you need to find it out if you are working with Italian customers.
[ExtensionOf(tableStr(CustTable))]
final class MYCustTable_Extension
{
public boolean checkVATNumUsed()
{
SysInfologLevel origInfologLevel = infolog.infologLevel(); // Capture current setting for infolog level
infolog.setInfoLogLevel(SysInfologLevel::None); // Suppress infolog
next checkVATNumUsed(); // You always need to call the standard logic...
infolog.setInfoLogLevel(origInfologLevel); // Return infolog setup to original
return true; // ....but you can ignore the return value and always return true
}
}