Extreme Android User
Aug 17, 2010
Cotswolds, England
Only 11 days after the initial release of stock Android 12, Samsung have begun rolling out their second official stock update of Android 12, One UI 4, for the S21 series of international devices.

With a Build date of just 3 days ago, it would seem that this is a bugfix update.

Initially, as always, this is a staged rollout to the non-carrier branded, stock Samsung CSC codes first.

The Galaxy S21 international devices that will receive this update are...

  • S21 5G model SM-G991B
  • S21+ 5G model SM-G996B
  • S21 Ultra 5G model SM-G998B
This latest release replaces the previous G99*BXXU3BUK8 build on the international devices.

It is a FOTA, (Firmware Over The Air), update and you can check... Settings > Software update... to see if it is available for you. Alternatively, you can connect to the Samsung PC suite, Smart Switch and check via that.

System information


The update = G99*BXXU3BUKG

Download = 330.59MB

Build date = 23 November 2021

Release date = 26 November 2021

Camera version = (no change)

One UI version = 4.0

Android Security patch = 01 November 2021

This is the 21st stable update for the Exynos model in 305 days. Average = 1 update every 15 days.

TOP TIP: Wipe the phone's cache partition and use the Galaxy App Booster after updating.

(N.B. This post will be updated as more information becomes available)
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I must say that I am impressed with the battery life on this BUKG update.

Normally I do not comment on battery life until the phone settles down after 2 or 3 charge cycles but this first charge since updating with 75% used and no Power saving is looking good. Certainly as good as Android 11, if not better. Am really liking this BUKG update so far.

The BUKG update is now available in the U.K. for...

Samsung stock devices on CSC code BTU

EE carrier branded devices on CSC code EVR

No news on Vodafone (VOD), O2 (O2U) or Three (H3G) updates yet.
Samsung are pushing ahead now with the roll-out of this bugfix firmware, BUKG, and have released over 50 updates for devices for countries and carriers in Europe already.

Three network carrier branded phones, H3G, are now the only ones still waiting on it in the U.K... as usual.

Looks like we will be in for another update shortly as Samsung will need to roll out the December Android Security patch in the near future.