SOMPRODUCT from different columns multiplied by VAT factor

I'm trying to solve a problem with SOMPRODUCT formula.

The invoice nummer are entered by the manufacturer in a sheet. It is possible that the manufacturer enters the invoice number on different rows in a certain column.
I want to check the total amount of money on these invoices:
1. I want the total price excl. VAT (this is no issue and works)
2. I want the total price inclusive the right 6% and 21% of VAT

I guess it is an altering of the formula in cell B12 but I have no idea how to change it.

Will you please attach a sample Excel workbook? Many members will not or cannot access file-sharing sites.

1. Make sure that your sample data are REPRESENTATIVE of your real data. The use of unrepresentative data is very frustrating and can lead to long delays in reaching a solution.

2. Make sure that your desired solution is also shown (mock up the results manually).

3. Make sure that all confidential data is removed or replaced with dummy data first (e.g. names, addresses, E-mails, etc.).

4. Try to avoid using merged cells as they cause lots of problems.

Unfortunately the attachment icon doesn't work at the moment, so to attach an Excel file you have to do the following: just before posting, scroll down to Go Advanced and then scroll down to Manage Attachments. Now follow the instructions at the top of that screen.

Please pay particular attention to point 2 (above): without an idea of your intended outcomes, it is often very difficult to offer appropriate advice.

First I put your VAT numbers in a separate row (row 2) and custom formatted them so that entering a number, they appear as #% VAT.

Then use this formula
=SUMPRODUCT(((A2:D2)+1)*(A3:D9)*(E3:E9=$B$12))
Does that work for you?