In most cases, the Toad for Oracle license keys do not change when authorizing being versions.
However, starting in with Toad for Oracle version 12.5, the old style legacy key will no longer be supported. The legacy key has a format of 1-12345-12345-12345-12345, (Twenty- one digits). This key format is no longer supported starting in Toad 12.5 and need to be upgraded.
The “new format” key (introduced in 2009) offers higher encryption and provides greater flexibility. The new license key is a long string of alphanumeric characters. All old format license keys will need to be upgraded to the new format keys if upgrading Toad for Oracle to newer versions.
This Knowledge Article offers resolutions in self servicing in in license key upgrading, license number locating and how to contact Licensing Assistance.
Knowledgebase Article 125978 can be viewed here.