Looking for punctual invoice check by certified accountants, 2-4 times a year: European division

Toelichting op de werkzaamheden
We are looking for punctual invoice check by certified accountants.
The work consists of checking that the amount invoiced by our supplier is based on detailed actual expenses plus reasonable margin.
We are the European division of our company.

For example:
We made a shooting for a TV add with Supplier A.
They invoiced us 1 Million euro and they used 25 sub-suppliers.
We would like an external source to check the invoices of the sub-suppliers and relate it to the invoice we get from supplier.

How Often:
We have these spends 2 to 4 times a year.

Offerte:
Thank you in advance to contact me if you can submit a quotation.

Wat is uw bedrijfsvorm? BV
Aantal medewerkers (included yourself): More than 20

Korte beschrijving bedrijfsactiviteiten
We are an international company based in several companies throughout the world.
Our mail business is cameras and other technical goods and services.