Add IF IS BLANK argument to existing formula

This is the basis of the formula

in VENDOR REPORT A2
=IFERROR(INDEX(MAINDATA!$A$2:$T$1000,AGGREGATE(15,6,ROW($A$2:$A$1000)/((ISNUMBER(MAINDATA!$Q$2:$Q$1000)=FALSE)),ROWS(A$2:A2))-(2-1),1),"")
in B2
=IFERROR(INDEX(MAINDATA!$A$2:$T$1000,AGGREGATE(15,6,ROW($A$2:$A$1000)/((ISNUMBER(MAINDATA!$Q$2:$Q$1000)=FALSE)),ROWS(A$2:A2))-(2-1),2),"")
in C2
=IFERROR(INDEX(MAINDATA!$A$2:$T$1000,AGGREGATE(15,6,ROW($A$2:$A$1000)/((ISNUMBER(MAINDATA!$Q$2:$Q$1000)=FALSE)),ROWS(A$2:A2))-(2-1),4),"")
in D2
=IFERROR(INDEX(MAINDATA!$A$2:$T$1000,AGGREGATE(15,6,ROW($A$2:$A$1000)/((ISNUMBER(MAINDATA!$Q$2:$Q$1000)=FALSE)),ROWS(A$2:A2))-(2-1),10),"")
in E2
=IFERROR(INDEX(MAINDATA!$A$2:$T$1000,AGGREGATE(15,6,ROW($A$2:$A$1000)/((ISNUMBER(MAINDATA!$Q$2:$Q$1000)=FALSE)),ROWS(A$2:A2))-(2-1),14),"")
in F2
=IFERROR(INDEX(MAINDATA!$A$2:$T$1000,AGGREGATE(15,6,ROW($A$2:$A$1000)/((ISNUMBER(MAINDATA!$Q$2:$Q$1000)=FALSE)),ROWS(A$2:A2))-(2-1),7),"")

Column G is now redundant since it will always contain spaces

NOTE: I'm not sure why zeroes are appearing, this is a standard formula I use with amended parameters to reflect your data. I've never had this problem before but the only condition set ifor column Q to be blank which it looks like they are.

That is cool, but my head hurts trying to figure out what it's doing!

Tim

AGGREGATE 15 is equivalent to SMALL

I used to have a detailes explanation of how this works but cant find it.

If you search for remove blanks from list or INDEX SMALL it should turn up lots of versions of this formula - some with explanation.
I'm afraid I'm at work so haven't got time to explain it fully.

Please try at

A2
=IFERROR(INDEX(MAINDATA!$A:$A,AGGREGATE(15,6,ROW(MAINDATA!$Q$2:$Q$99)/(MAINDATA!$Q$2:$Q$99=0)/(MAINDATA!$A$2:$A$99>0),ROWS(A$2:A2))),"")

B2:F2
=IF($A2="","",VLOOKUP($A2,MAINDATA!$A$2:$T$39,MATCH(B$1,MAINDATA!$A$1:$T$1,),))

E2
=IF($A2="","",IFERROR(1/(1/VLOOKUP($A2,MAINDATA!$A$2:$T$39,MATCH(E$1,MAINDATA!$A$1:$T$1,),)),""))


or if you have update Office 365, Dynamic array should available
A2
=FILTER(MAINDATA!$A$2:$A$99,(MAINDATA!$Q$2:$Q$99="")*MAINDATA!$A$2:$A$99)