@hdeshev commented on @T_GDB’s file https://netsuiteprofessionals.slack.com/files/U7VH2756H/F9X5ME42K/hello_guys__i_received_that_permission_error_when_i_would_like_to_change_the_quantities_of_the_fulfillment_.txt: @T_GDB That permission error can happen if your form has the field hidden or displayed as read only. I'd double check what custom form the API call uses when updating fulfillments and possibly design an API-only form that has the field enabled. Trying to link to the "Forms in Web Services" help article... https://system.eu2.netsuite.com/app/help/helpcenter.nl?fid=section_N3439676.html