SUMPRODUCT accross multiple spreadsheets not working

[MillyP]

Hi there,
I'm trying to sum data from several tabs based on the date a payment was made.

I have a summary page where Column A lists the tab names in the workbook and Row B contains the dates.

Each tab lists the payments schedule for an individual supplier.

I have this formula in the summary sheet:-

=SUMPRODUCT(SUMIF(INDIRECT("'"&$A$6:$A$20&"'!$f$19:f100"),B$4,INDIRECT("'"&$A$6:$A$20&"'!g19:g100")))

I want the formula to look column F in each tab (the date) and add all the values in column G if the date in column F matches the date in row B on the summary sheet,

The formula only works on the first row (for CO):-

The figures for DECC HCT, DECC JL and PHE are not calculating.

Can anyone help please?


[TABLE="width: 638"]
<tbody>[TR]
[TD]Organisation[/TD]
[TD="align: right"]28-Feb-14[/TD]
[TD="align: right"]31-Mar-14[/TD]
[TD="align: right"]30-Apr-14[/TD]
[TD="align: right"]31-May-14[/TD]
[TD="align: right"]30-Jun-14[/TD]
[/TR]
[TR]
[TD]Column1[/TD]
[TD]April[/TD]
[TD]May[/TD]
[TD]June[/TD]
[TD]July[/TD]
[TD]August[/TD]
[/TR]
[TR]
[TD]CO[/TD]
[TD] 159,950[/TD]
[TD] 164,955[/TD]
[TD] 152,663[/TD]
[TD] 160,165[/TD]
[TD] 145,638[/TD]
[/TR]
[TR]
[TD]DECC HCT[/TD]
[TD] 159,950[/TD]
[TD] 164,955[/TD]
[TD] 152,663[/TD]
[TD] 160,165[/TD]
[TD] 145,638[/TD]
[/TR]
[TR]
[TD]DECC JL[/TD]
[TD] 159,950[/TD]
[TD] 164,955[/TD]
[TD] 152,663[/TD]
[TD] 160,165[/TD]
[TD] 145,638[/TD]
[/TR]
[TR]
[TD]PHE[/TD]
[TD] 159,950[/TD]
[TD] 164,955[/TD]
[TD] 152,663[/TD]
[TD] 160,165[/TD]
[TD] 145,638[/TD]
[/TR]
</tbody>[/TABLE]