hi, trying to use this formula for IF saved search but getting an invalid expression, any ideas?

CASE WHEN {appliedtotransaction.custcol_celigo_etail_order_line_tax} IS NULL THEN '0' ELSE {appliedtotransaction.custcol_celigo_etail_order_line_tax} END

Is that tax field a string? If not, remove the quotes around the 0.

Have you tried something along the lines of:

NV({appliedtotransaction.custcol_celigo_etail_order_line_tax},0)

oh!! that worked, yes it is a tax field and totally removing the quotes fixed it