My formula works with the first cell and gives me a correct return value.

=VLOOKUP(C3,'Gas Data'!$C$3:$F$840,4,FALSE)

When the formula is dragged down I get the following:-

=VLOOKUP(C4,'Gas Data'!$C$3:$F$840,4,FALSE)

This formula in theory should be correct, as the lookup value I am trying to match is column C and the return value in column F of the separate tab.

However, all I get is #N/A.

Any help would be much appreciated as the match lookup value is correct and I can find it manually in 'Gas Data'

Thanks