Hstack Problem

[pto160]

I am trying to add an extra column using the Hstack function. The third column I need to use a Text join using the delimiter ":" for the refunds who are duplicate customers and the other ones just the single refund. Here is the data.

Book1
	A	B	C
1	Name	Amount	Voucher
2	John Smith	50	10020
3	Paul Rudd	100	10021
4	John Smith	200	10022
5	Jane Smith	500	10023
6
7	=HSTACK(UNIQUE(A2:A5),SUMIFS(B2:B5,A2:A5,UNIQUE(A2:A5)))
8
9	What I want:
10	Name	Amount	Voucher
11	John Smith	250	10020:10022
12	Paul Rudd	100	10021
13	Jane Smith	500	10023
Sheet1

 

[pto160]

These are great formulas. With the reduce formula,

=REDUCE(A1:C1,A2:A5,LAMBDA(x,y,IF(OR(y=x),x,VSTACK(x,HSTACK(y,SUMIF(A:A,y,B:B),TEXTJOIN(":",,FILTER(C:C,A:A=y)))))))

I have an extra column for ID, that I would doing the sum criteria on instead of name but I would like to see both name and ID.
How would I add the extra column? The reduce formula is accounting for 3 columns- Name, Amount and Voucher.

Book2
	A	B	C	D
1	Cust ID	Name	Amount	Voucher
2	100	John Smith	50	10020
3	200	Paul Rudd	100	10021
4	100	John Smith	200	10022
5	300	Jane Smith	500	10023
6
7
8	What I would like
9	Cust ID	Name	Amount	Voucher
10	100	John Smith	250.00	10020:10022
11	200	Paul Rudd	100.00	10021
12	300	Jane Smith	500.00	10023
Sheet1