All Splash licences include upgrades and bug fixes within the same major version (eg 3.xx.x)
Licences for Splash 1 or 2 can be upgraded by purchasing the upgrade - select the upgrade option from the first selection on the Buy page.
When upgrading, you will also need to send us the existing licence. This can be included with the order, if submitting an order to be invoiced later. If buying with a card, please send us a message via the contact form with your existing licence. (And please include the email used to place the order, if it is different to the one you use with the contact form)
For the existing licence you can either send the entire code, or just the name which appears at the beginning of it. You can also find this name within the software - select from the menu > Help > Enter new licence, and the first item on that screen ("current licence name") is the name we need for the upgrade.