I signed up for a monthly usage plan, but I haven’t received a serial number or activation code.
Neither serial numbers (30-character alphanumeric codes starting with SP), nor 12-character activation codes are issued when signing up for Clip Studio Paint Monthly usage plans.
Note: the same applies for plans billed annually.
Activating your plan
After applying for a monthly usage plan, you will need to authenticate your license to use the app.
Refer below for authentication instructions for your device.