M556BXXU4CYJ4 – Galaxy M55 5G firmware

Build M556BXXU4CYJ4 is a feature update for the Galaxy M55 5G (SM-M556B) on Android 16 (One UI 8). It first appeared on Samsung's servers on Oct 26, 2025 (method) and has reached 13 regions so far. It keeps bootloader bit 4, so downgrading to the previous build M556BXXS4BYH2 is still possible. Samsung still serves this file.

Model
SM-M556B
Android
Android 16
Type
Feature
Bootloader bit
4
First released
Oct 26, 2025
Regions
13

Rollout timeline by region

The date each region code (CSC) first received M556BXXU4CYJ4, counted from the first release.

CSCRegionReleasedRolloutVersion (PDA/CSC/MODEM)
INSIndiaOct 26, 2025day 0M556BXXU4CYJ4/M556BODM4CYJ4/M556BXXU4CYJ4
NPBNepalOct 26, 2025day 0M556BXXU4CYJ4/M556BODM4CYJ4/M556BXXU4CYJ4
SLKSri LankaOct 26, 2025day 0M556BXXU4CYJ4/M556BODM4CYJ4/M556BXXU4CYJ4
EGYEgyptOct 30, 2025+4 daysM556BXXU4CYJ4/M556BOJM4CYJ4/M556BXXU4CYJ4
ILOIsraelOct 30, 2025+4 daysM556BXXU4CYJ4/M556BOJM4CYJ4/M556BXXU4CYJ4
MIDMiddle EastOct 30, 2025+4 daysM556BXXU4CYJ4/M556BOJM4CYJ4/M556BXXU4CYJ4
XXVVietnamOct 30, 2025+4 daysM556BXXU4CYJ4/M556BOLM4CYJ4/M556BXXU4CYJ4
TPAPanamaOct 30, 2025+4 daysM556BXXU4CYJ4/M556BOWO4CYJ4/M556BXXU4CYJ4
CHOChileNov 4, 2025+9 daysM556BXXU4CYJ4/M556BOWO4CYJ4/M556BXXU4CYJ4
PEOPeruNov 4, 2025+9 daysM556BXXU4CYJ4/M556BOWO4CYJ4/M556BXXU4CYJ4
ZTOBrazilNov 4, 2025+9 daysM556BXXU4CYJ4/M556BOWO4CYJ4/M556BXXU4CYJ4
BNGBelgiumNov 12, 2025+17 daysM556BXXU4CYJ4/M556BODM4CYJ4/M556BXXU4CYJ4
COOColombiaNov 13, 2025+18 daysM556BXXU4CYJ4/M556BOWO4CYJ4/M556BXXU4CYJ4

Download and release notes

samloader download -m SM-M556B -r INS -v M556BXXU4CYJ4/M556BODM4CYJ4/M556BXXU4CYJ4

Samsung's release notes and security patch level for this update: SM-M556B / INS on doc.samsungmobile.com. What each part of the build number means: decode M556BXXU4CYJ4.