4.3.33Independent Auditor’s Fees and Services

Fees included in other operating costs related to PwC, the 2021 and 2020 Company’s external independent auditor, are summarized as follows:

in thousands of US$

2021

2020

Audit of financial statements

2,768

2,526

Out of which:

- invoiced by PwC Accountants N.V.

1,822

1,522

- invoiced by PwC network firms

946

1,004

Tax advisory services by PwC network firms

33

50

Other assurance services

136

113

Total

2,937

2,689

In both 2021 and 2020, the other assurance services were mainly related to the review of the Company sustainability report.