Yes, contractors can upload new OSHA 300 logs into ISNetworld. Contractors need to be aware that Hiring Clients / Owner Clients will see previous OSHA 300 logs that have been uploaded. Contractors that have a legitimate reason for correcting their logs or those jockeying the grades typically will need to answer to their customers on why they changed their OSHA 300 logs. It is not uncommon for the uninformed contractor to upload 3 and 4 OSHA logs for the same year without knowing the tracking history created and the impression left with Hiring Clients.