A566U1UESBCZI2 – Galaxy A56 5G firmware

Build A566U1UESBCZI2 is a security update for the Galaxy A56 5G (SM-A566U1) on Android 16 (One UI 8). It first appeared on Samsung's servers on Sep 15, 2026 (method) and has reached 11 regions so far. It raises the bootloader bit from 10 to 11: once installed, the device no longer accepts firmware with bit 10 or lower, so a downgrade to A566U1UESACZHB is blocked. Samsung still serves this file.

Model
SM-A566U1
Android
Android 16
Type
Security
Bootloader bit
11
First released
Sep 15, 2026
Regions
11

Rollout timeline by region

The date each region code (CSC) first received A566U1UESBCZI2, counted from the first release.

CSCRegionReleasedRolloutVersion (PDA/CSC/MODEM)
ACGUSA (C Spire)Sep 15, 2026day 0A566U1UESBCZI2/A566U1OYMBCZI2/A566U1UESBCZI2
AIOUSA (Cricket)Sep 15, 2026day 0A566U1UESBCZI2/A566U1OYMBCZI2/A566U1UESBCZI2
ATTUSA (AT&T)Sep 15, 2026day 0A566U1UESBCZI2/A566U1OYMBCZI2/A566U1UESBCZI2
CCTUSA (Comcast)Sep 15, 2026day 0A566U1UESBCZI2/A566U1OYMBCZI2/A566U1UESBCZI2
LRAUSA (Bluegrass)Sep 15, 2026day 0A566U1UESBCZI2/A566U1OYMBCZI2/A566U1UESBCZI2
TMBUSA (T-Mobile)Sep 15, 2026day 0A566U1UESBCZI2/A566U1OYMBCZI2/A566U1UESBCZI2
TMKUSA (MetroPCS)Sep 15, 2026day 0A566U1UESBCZI2/A566U1OYMBCZI2/A566U1UESBCZI2
USCUSA (US Cellular)Sep 15, 2026day 0A566U1UESBCZI2/A566U1OYMBCZI2/A566U1UESBCZI2
VZWUSA (Verizon)Sep 15, 2026day 0A566U1UESBCZI2/A566U1OYMBCZI2/A566U1UESBCZI2
XAAUSA (unlocked)Sep 15, 2026day 0A566U1UESBCZI2/A566U1OYMBCZI2/A566U1UESBCZI2
XARUSA (Cellular South)Sep 15, 2026day 0A566U1UESBCZI2/A566U1OYMBCZI2/A566U1UESBCZI2

Download and release notes

samloader download -m SM-A566U1 -r XAA -v A566U1UESBCZI2/A566U1OYMBCZI2/A566U1UESBCZI2

Samsung's release notes and security patch level for this update: SM-A566U1 / XAA on doc.samsungmobile.com. What each part of the build number means: decode A566U1UESBCZI2.