Subscription licenses automatically receive free upgrades for as long as the subscription remains active.
For perpetual licenses, Pixologic guarantees free upgrades for one year from date of purchase. Anything beyond that is entirely at Pixologic's discretion.
To date, Pixologic has never charged for an upgrade. Even people who bought the very first version of ZBrush in 1999 have received free upgrades for every version to date, despite significant changes in price over these many years.
Due to this extremely generous upgrade history, many people mistakenly believe that our licenses come with lifetime free upgrades. This is not the case. At some point we will undoubtedly start charging for upgrades. However, until that happens we have no way to know what the actual cost or procedures might be.
Academic licenses may be upgraded to a commercial license at any time by submitting a Support ticket. The cost of this upgrade is 50% of the commercial license price at time of upgrade. Once upgraded, all assets that you created while using an academic license are now considered to have been created under a commercial license and may be used for profit.