https://api.mailjet.com/v3/REST/contactslist/{list_id}/ManageManyContacts/{job_id} C# api ALLOWS for this by using the ActionId MailjetRequest request = new() { Resource = ContactslistManagemanycontacts.Resource, ResourceId = ResourceId.Numeric(contactslistId), ActionId = jobId }; Documentation here is incorrect (https://dev.mailjet.com/email/reference/contacts/bulk-contact-management/#v3_get_contactslist_list_ID_managemanycontacts_job_ID)