Equivalent of worksheetfunction.sumif for an array

Hello,
I have 2 arrays.
1st array (POlist) is a list of PO numbers, which can change.
2nd array (InvoiceAmounts) is a list consisting of a PO (Column A) & corresponding invoice amounts (Column B) as shown below.

PO Invoice
1 234
2 856.5
5 655.51
1 5656.6
2 1565.54
1 130
5 98.57

So PO 1 would be 6,020.60
PO 2 would be 2,422.04
etc

I would like to find an efficient way sum all the $ amounts per PO in POlist. I would prefer to avoid looping though the invoice amounts numerous times if possible.
I tried to use worksheetfunction.sumif, but after some research, I found out that this will not work since an array is not a range.

Any ideas would be greatly appreciated.

Originally Posted by protonLeah

post the workbook with the vb code you are using

Example_SumifArray.xlsm

Hi ProtonLeh, Please see the attached.