I do have another way which is working for me (below). I just wanted to try this other way to see if works more efficient.
IF (
(@Client = 'Winco Foods'
AND EXISTS
( SELECT 1
FROM ClaimSummary_Winco CSW
WHERE CSW.AuditNbr is null
OR CSW.VndNbr is null
OR CSW.VndName is null
OR CSW.CompanyCode is null
OR CSW.AuditorID is null
OR CSW.ClmAmt is null
OR CSW.PRGCode is null
OR CSW.[Year] is null
OR CSW.ClmNbr is null
OR CSW.CompanyCode is null
)
)