FortiGate-VM offers perpetual licensing (normal series and v-series) and annual subscription licensing. See VM license for details.
After you submit an order for a FortiGate-VM, Fortinet sends a license registration code to the email address that you entered on the order form. Use this code to register the FortiGate-VM with Customer Service & Support, then download the license file. After you upload the license to the FortiGate-VM and validate it, your FortiGate-VM is fully functional.