If you've created a CELSYS account (the company behind Clip Studio Paint), you may be able to find your serial number associated with your account:
If you are in the remaining 10%—the registry is corrupted, the email is deleted, and the hard drive is fried—take a deep breath. Gather every shred of payment evidence you can find, contact Japanese support politely, and wait. CELSYS is known for being reasonable with legitimate owners, provided you can prove you paid.
If you have Clip Studio Paint installed on your computer, you can try to find your serial number within the software:
Finding your Clip Studio Paint (CSP) serial number depends on how you originally acquired the software—whether through a direct purchase, a bundled tablet, or a modern subscription plan. 1. Check Your Email (Most Reliable)
