SUMIFS and exclude Duplicates

I am trying to use SUMIFS, but want to exclude duplicate values. I have the following formula:

=SUMIFS(Table_POs[PO_BAL_AMT],Table_POs[Type of Service],"=Appraising Services",Table_POs[BUD_REF],"2015",Table_POs[Code],$E$2,Table_POs[PO_NUMBER],"<>Table_POs[PO_NUMBER]")

My intent is to sum the values in the [PO_BAL_AMT] column where The [Type of Service], [BUD_REF], and [CODE] conditions are met, but exclude duplicate amounts. In the attached spreadsheet, there can be multiple entries for a single [PO_NUMBER] due to different [INVOICE_ID] numbers. I only want to sum the [PO_BAL_AMT] once for each [PO_NUMBER].

I hope this makes sense and thank you for your help,
Mark

Try the attached. PO value column label should be PO_BAL_AMT

Possible Answer 416566d1441043588-sumifs-and-exclude-duplicates-mark-sample.xlsx

Pete

This works. However I may need some additional help.
Is there a way do this without the helper columns? My final goal is to be able to calculate the remaining PO Balance amounts based on the code, service type, and budget year. Similar to the formulas that are in D65:D69.
Thanks for your time and help, it is appreciated.

Where do you need the PO result displayed?

It will be on a different tab. I didn't include it my original attachment because some of the information is sensitive. I should be able to copy a formula into the location, so if you show it in D65 I should be able to move it.