Assuming there are no empty cells within the range in column A, try this
array formula:

=SUM(IF(FREQUENCY(IF(MATCH(A1:A10,A1:A10,0)=ROW(A1 :A10)-MIN(ROW(A1:A10))+1,ROW(A1:A10)),ROW(A1:A10)),B1:B1 0))

Adjust ranges to suit.

** array formulas need to be entered using the key combination of
CTRL,SHIFT,ENTER (not just ENTER)

--
Biff
Microsoft Excel MVP


"Graham" wrote in message
...
The value in column B always matches with the value in column A, eg
NJ?64907/60388 in column A will always have the same value 19.98, this
value will not change in column B, the pair are inique.

T. Valko wrote:
Is it possible to have duplicates in column A with unique values in
column B?

NJ/64907/60388 19.98
NJ/64907/60388 19.98
NJ/64907/60388 12.25

And in this case you'd only want to sum 19.98 and 12.25 (32.23) ?