Approval of Secondary Income Secondary income must be officially approved for all members of the chair. Members are -- to our current knowledge -- officially allowed to work up to 120% in total, so if one has a 80% position, working on four days a week, one could work two more days. If you have been invited to teach somewhere give a paid talk somewhere make a paid book review somewhere or sit in a committee where you will be paid for your work You must ask the chair holder for approval in written form. Information on the approval process can be found online at this link . The form that must be filled can be found on this link . Once a year, all those who have had secondary income must sign a form that proves the amount of money and tells explicitly whether university resources were used for the work. This form can be found here .