Your snippet does not validate the routing number "111000960" -- or any other number I tried ending in 0. In this case, it rerturns 10 not 0.

So this seemed to work:

;WITH numbers AS ( select NUMBER as n from dbo.F_TABLE_NUMBER_RANGE(1,9) )

SELECT @isValid = CASE

WHEN LEN(@RoutingNumber)=9

AND @RoutingNumber NOT LIKE '%[^0-9]%' --Check to make sure is all digits

AND RIGHT(@RoutingNumber ,1) = right((

--==== Calculates check digit (Digit 9)

SELECT 10-SUM(mv.DigitVal)%10 --Sum of individual digit values subtracted for new number ending in 0

FROM (--==== Gets multiplied value for each digit in 3, 7, 1 pattern

SELECT CASE

WHEN (t.N-1)%3 = 0 THEN SUBSTRING(@RoutingNumber,t.N,1)*3 --Digits 1,4,7

WHEN (t.N-1)%3 = 1 THEN SUBSTRING(@RoutingNumber,t.N,1)*7 --Digits 2,5,8

WHEN (t.N-1)%3 = 2 THEN SUBSTRING(@RoutingNumber,t.N,1)*1 --Digits 3,6

END AS DigitVal

FROM numbers as t

WHERE t.N <= 8

) as mv

),1)

THEN 1

ELSE 0

END