Samsung Model Numbers & CSC Codes Explained (SM-S928B, U, N, E…)

Two Galaxy phones can look identical, run the same One UI version and still behave very differently: one gets Wi-Fi calling on your network and the other doesn’t, one accepts your SIM and the other asks for an unlock code, one has an Exynos chip and the other a Snapdragon. The difference is written in two short codes almost nobody reads — the model number and the CSC.

Once you can read them, you can tell where a Samsung was built to be sold, which carrier it was configured for, whether its firmware has been swapped and whether the listing you’re looking at is honest.

Anatomy of a Samsung model number

Take SM-S928B, the international Galaxy S24 Ultra. It splits into four parts:

The digits move up with each generation (for example S92x for the S24 series, S93x for the S25 series), and the last digit roughly ranks the tier inside a family. A-series numbers follow a similar idea: higher numbers generally mean higher-end models within a year.

What the suffix letters usually mean

Samsung doesn’t publish a master list, and suffixes have shifted over the years and between product lines. As a working guide for recent phones:

The suffix also tells you about the chip on some generations. Samsung has historically shipped Snapdragon in the US, Canada and China and Exynos in other markets for some flagship generations, while other generations used Snapdragon worldwide. Check the specific model rather than assuming.

What CSC means

CSC stands for Consumer Software Customization. It’s a three-letter code that tells the firmware which country and carrier configuration to load. The same SM-S928B hardware behaves differently depending on its CSC:

• Network features: VoLTE, Wi-Fi calling, 5G standalone and carrier-specific settings are switched on or off per CSC.
• Preinstalled apps and branding: carrier apps, boot animations and default APN settings.
• Update channel: firmware updates are released per region and carrier, so two identical phones can receive updates on different days.
• Language and features: some features (call recording, certain camera or payment options) are enabled or disabled per market.

Examples you may see: XEU (UK unlocked), BTU (UK), EUX (Europe), DBT (Germany unlocked), XAA (US unlocked), TMB (T-Mobile US), ATT (AT&T), VZW (Verizon), INS (India). Lists online vary, so use these as examples rather than a reference table.

Single-CSC vs multi-CSC firmware

Modern Samsung firmware is usually multi-CSC: one firmware package (with a code such as OXM or OXA) contains configurations for many countries. The phone picks the active CSC from the sales code stored at the factory. That’s why you’ll often see two or three codes listed together — the firmware package, the active CSC and the original sales code.

How to see the model number and CSC

In Settings

• Settings › About phone — shows Model name and Model number (for example SM-S928B/DS).
• Settings › About phone › Software information › Service provider software version — shows lines such as SAOMC_SM-S928B_OXM_EUX_... and, below it, something like EUX/EUX/DBT. Read it as: firmware package OXM, active CSC EUX, and the remaining codes as configured/original sales codes.
• Settings › About phone › Software information — also shows the Baseband version and Build number discussed below.

From the dialer

Samsung supports a few service codes. Type them in the Phone app keypad (no need to press call):

*#06#
*#1234#
*#0*#

• *#06# — shows the IMEI(s), serial number and sometimes the EID.
• *#1234# — shows AP, CP and CSC firmware versions, useful to confirm the firmware matches the model.
• *#0*# — opens the hardware test menu on many Galaxy phones (screen colors, touch, sensors). Press Back to exit. Some carrier models disable it.

Reading a firmware version string

A build number like S928BXXS3AXK1 packs a lot of information:

• S928B — the model it was built for. If this doesn’t match the model in Settings, the phone has been flashed with another variant’s firmware.
• XX — the region group the firmware was compiled for.
• S — update type (commonly U for a feature update, S for a security-only update).
• 3 — the binary (bootloader) revision. This matters: Samsung generally blocks flashing firmware with a lower binary number, so you can’t simply roll back.
• A — major software iteration since launch.
• X — year letter; K — month (A = January through L = December); 1 — build within that month.

A mismatch between the model in Settings, the build string and the box is one of the clearest signs that a phone has been cross-flashed, repaired with a board from another variant or misrepresented by the seller.

Using model and CSC when buying a used Galaxy

1. Match the model to the listing. A “global unlocked S24 Ultra” should show a B or U1 style suffix, not a U carrier model that might be locked.
2. Check the CSC against the claim. A CSC like TMB or VZW means the phone was configured for a US carrier — run a carrier and SIM-lock check before you pay.
3. Confirm the IMEI belongs to that model. A manufacturer and model check confirms the IMEI’s registered model, while the Samsung Info S2 report (IMEI or serial) adds sales country and warranty details.
4. Check the blacklist. A clean model and CSC don’t tell you about theft reports — run a GSMA blacklist check.
5. Look at Knox and accounts. See our guide to checking a used Samsung for Samsung account, FRP and Knox signs.

Can you change the CSC?

On some unlocked Galaxy phones with multi-CSC firmware, the active CSC can switch to another country in the same firmware group (typically after inserting a local SIM and resetting), or be changed by a service center. It usually requires a full factory reset, and it doesn’t change the hardware, the radio bands or the carrier lock. Changing the CSC of a carrier-locked phone doesn’t unlock it — the SIM lock is a separate setting tied to the device, which only the carrier can lift. If you need that, read locked vs unlocked phones explained.

Check a Samsung now

Our Samsung IMEI check page explains every report. Or run one directly here — enter the IMEI from *#06#: