A556BXXSIDZI3 – Galaxy A55 5G firmware

Build A556BXXSIDZI3 is a security update for the Galaxy A55 5G (SM-A556B) on Android 16 (One UI 8). It first appeared on Samsung's servers on Sep 20, 2026 (method) and has reached 16 regions so far. It raises the bootloader bit from 17 to 18: once installed, the device no longer accepts firmware with bit 17 or lower, so a downgrade to A556BXXSHDZH6 is blocked. Samsung still serves this file.

Model
SM-A556B
Android
Android 16
Type
Security
Bootloader bit
18
First released
Sep 20, 2026
Regions
16

Rollout timeline by region

The date each region code (CSC) first received A556BXXSIDZI3, counted from the first release.

CSCRegionReleasedRolloutVersion (PDA/CSC/MODEM)
BOGFrance (Bouygues)Sep 20, 2026day 0A556BXXSIDZI3/A556BOXMIDZI3/A556BXXSIDZI3
EUXEurope (Multi-CSC)Sep 20, 2026day 0A556BXXSIDZI3/A556BOXMIDZI3/A556BXXSIDZI3
EUYEurope (Multi-CSC)Sep 20, 2026day 0A556BXXSIDZI3/A556BOXMIDZI3/A556BXXSIDZI3
EVRUnited Kingdom (EE)Sep 20, 2026day 0A556BXXSIDZI3/A556BOXMIDZI3/A556BXXSIDZI3
MEOPortugal (MEO)Sep 20, 2026day 0A556BXXSIDZI3/A556BOXMIDZI3/A556BXXSIDZI3
MOBAustria (A1)Sep 20, 2026day 0A556BXXSIDZI3/A556BOXMIDZI3/A556BXXSIDZI3
MOTSlovenia (Telekom)Sep 20, 2026day 0A556BXXSIDZI3/A556BOXMIDZI3/A556BXXSIDZI3
MSRSerbiaSep 20, 2026day 0A556BXXSIDZI3/A556BOXMIDZI3/A556BXXSIDZI3
O2CCzech Republic (O2)Sep 20, 2026day 0A556BXXSIDZI3/A556BOXMIDZI3/A556BXXSIDZI3
PLSPoland (Plus)Sep 20, 2026day 0A556BXXSIDZI3/A556BOXMIDZI3/A556BXXSIDZI3
PRTPoland (Play)Sep 20, 2026day 0A556BXXSIDZI3/A556BOXMIDZI3/A556BXXSIDZI3
SFRFrance (SFR)Sep 20, 2026day 0A556BXXSIDZI3/A556BOXMIDZI3/A556BXXSIDZI3
SIMSlovenia (A1)Sep 20, 2026day 0A556BXXSIDZI3/A556BOXMIDZI3/A556BXXSIDZI3
SWCSwitzerlandSep 20, 2026day 0A556BXXSIDZI3/A556BOXMIDZI3/A556BXXSIDZI3
TOPSerbia/MontenegroSep 20, 2026day 0A556BXXSIDZI3/A556BOXMIDZI3/A556BXXSIDZI3
VIPCroatia (A1)Sep 20, 2026day 0A556BXXSIDZI3/A556BOXMIDZI3/A556BXXSIDZI3

Download and release notes

samloader download -m SM-A556B -r EUX -v A556BXXSIDZI3/A556BOXMIDZI3/A556BXXSIDZI3

Samsung's release notes and security patch level for this update: SM-A556B / EUX on doc.samsungmobile.com. What each part of the build number means: decode A556BXXSIDZI3.