Technically, no. REAPER will never lock you out. You could use it for years without paying a cent.
Required for professionals and businesses whose annual revenue from the software exceeds $20,000 USD. 2. Purchasing and Receiving the Key
If the software doesn't lock you out, why are so many people looking for illicit keys? Three psychological reasons:
: For individuals using REAPER for personal use, or for businesses/educational institutions with an annual gross revenue under $20,000.
While REAPER does not require constant internet, the license file contains a unique hash. Cockos has stated they periodically check license validity during updates. Using a blacklisted key (one shared publicly) will result in REAPER displaying: "Your license key has been revoked due to being published on the internet." You will then have to re-evaluate or buy a legitimate key.
