A new firmware update has started to roll out to the Sony Xperia Z1, which has just been released in the last few days across many countries. The firmware version number moves from the current build of 14.1.G.1.518 to build number 14.1.G.1.531. No noticeable changes have been found, so it’s likely a bug/performance update. The ‘531’ update is currently hitting HSPA+ handsets (C6902) in India, but should see a wider rollout shortly.
Thanks Anurag and Mitesh!