Samsung Firmware Details :

All Samsung Galaxy Series firmwares have three components that are as follows:
  1. PDA
  2. Phone
  3. CSC
The name of a firmware contains all these details. Thus, PDA refers to the build version of the software/firmware, Phone refers to the baseband/modem version, and CSC (Consumer Software Customization) denotes to a specific geographical region or carrier. The CSC code contains the info about software packages specific to a particular region, carrier branding and also APN (Access Point Name) settings for data connection.
In this way, unless the PDA, PHONE and CSC codes do not match correctly, you will not be able to update your device over Samsung Kies or via OTA.
Now remember that the product code and firmware version differs from one device to another according to the region or country where it is sold. In most cases you can find out the country or region of a device for which it has been made by referring to the firmware version.
In the above screenshot, for example, look at the Baseband version that is: I9300XXALE8. Here is an analysis of the baseband version of the Galaxy S3, for example:
  • “I9300″ is the device model number, that is Galaxy S3;
  • “XX” denotes to the Country/Region/Network code, that is Austria, Belgium, France, Germany, Hungary, Italy, Spain, United Kingdom;
  • “LE” points to the date of release of this firmware (L is the 12th character of the alphabet and E is the 5th, so it is May 12);
  • Finally “8″ shows the Revision version of the firmware.
Again, as the CSC  of a Samsung Galaxy phone firmware contains the code-name of the country/region for which it is build, you can change it to tell Samsung servers that your phone is actually from a different country/region and get official updates for that country. It often happens that a firmware update is released for a particular country and you do not get it in your country. You grab the firmware file but are afraid that you will not be able to get the future official updates on your Android device if you flash a firmware that is not meant for your country.
The idea of changing the CSC of you phone drops in here. Thus you can install a firmware from a different region and change the CSC of your phone with a little trick and everything goes fine.

How to Check/Discover the CSC of Galaxy Devices:
If you do not know the  CSC or product code of you Samsung Galaxy phone or tablet device, there are 2 ways to find it. You can check the CSC by connecting the device to computer via Samsung Kies. Another method is by dialing a code on your device’s dialer itself. Just dial *#1234# and you see a screen like shown below. The first 3 alphabets after your device model constitute the CSC code for your device (see below):
samsung-csc-code

How to Change CSC in Samsung Galaxy:

Please note that performing the CSC change action will factory reset your phone. It means it will take your phone to the status as it was when you bought it. All data present on the internal storage will be wiped. Therefore, do not forget to backup you data before you proceed.
  1. Open your phone’s dialer and type the following code with your device IMEI number: *#272*Phone’s IMEI Here
  2. You can find your phones IMEI number on a white sticker beneath phone’s battery.
  3. You will see a pop-up screen with a list of CSC codes. Change-CSC-SGS3
  4. Select the CSC that you want and tap on “Install”.
  5. Your phone will be reboot automatically.
  6. Congrats! Your Samsung Galaxy phone’s CSC has been changed successfully.

Change CSC Code on Galaxy S4 and Other Galaxy Devices:

If the above set of code *#272*Phone’s IMEI Here# did not work for you, try the CSC Changer app developed by bassie1995. I have tested it on my Galaxy S4 and it works like a charm. But unlike the above method it requires root access on your Samsung Galaxy device. You can later unroot your device by choosing “Full Unroot” option present under SuperSU Settings and then by flashing the stock Kernel.
Warning: Whatever method you chose to change CSC on your Galaxy phone or tablet, it is sure to wipe all data and apps present on the internal SD Card of your device. So act wisely and backup all data first.
  1. Download CSC Changer app and copy it to your phone by connecting to computer: CSC-Changer.apk
  2. If the above app does not work for you, try this app: cscselect-5.apk
  3. Also download the BusyBox app: stericson.busybox-141-v9.3.apk     (Google Play Link)
  4. Make sure you install the BusyBox first and CSC Changer requires it pre-installed to work.
  5. Open the CSC Changer app and select “Change CSC”.
  6. This will take you directly to the available CSC codes list on your device. Please note that you will be able to see many codes only if your device’s firmware has multi-CSC.galaxy-s4-csc-change
  7. Select your desired CSC and tap on “Install” option.
  8. You device will now reboot and when it wakes up, it’ll have the new CSC.
Congrats!

Recommended Reading:

While this trick works fine with Samsung Galaxy devices with Android 4.0.4, some users have reported it not working having upgraded to Jelly Bean firmware. In that case, follow the following steps and then try the above trick:
  1. Turn off your Samsung Galaxy phone
  2. Boot it into Recovery mode: press and hold Volume Up+ Home+Power keys simultaneously or a few seconds. Release the keys when you see the Recovery mode with blue text.
  3. Scroll down to “wipe data/factory reset” option using Volume key and select it using the Power key.
  4. Also wipe the cache.
  5. Then select “reboot system now’.
  6. When the phone boots up, try the CSC change code again.
If you do not want to go through this method, there is still another way you can change the CSC of your phone. Download a free app called Samsung Galaxy S / S2 / S3 CSC (link below) from the Google Play Store and install it. Run the app, follow the on-screen hints and done! In case this app does not work for on unrooted device, root your phone first and then try again.

Another Method:

(You phone must be running the stock ROM and have root access! Also, changing the CSC will wipe your phone’s data.)
  1. Download and install CSC Changer app on your Galaxy device.
  2. Run the app to find the CSC code of your device.csc-changer-samsung
  3. If you find your desired CSC just select it and tap the Install button.
  4. In case CSC Changer does not work for you, install ES File Manager app or any other root browser:
    ES File Explorer File Manager
    ES GlobalProductivityFree
    Download
  5. Launch the app, go to Root Explorer option and change R/O to R/W.ES-Explorer
  6. Navigate to /efs/imei/ folder, edit the CSC code in mps_code.dat file and save the changes.Screenshot_2013-06-28-16-34-19
  7. Then go to /system/csc/ folder and edit your CSC in sales_code.dat file.Screenshot_2013-06-28-16-34-39
  8. Now save the changes and reboot your device.
  9. Now install Triangle Away app and reset the custom flash counter: 
    [root] Triangle Away
    ChainfireTools$2.49
    Download
  10. Then download the stock firmware for your phone and install it using Odin.
  11. Having flashed the firmware, reboot into stock recovery to check if the new CSC has been applied or not.

List of CSC Codes for Samsung Firmwares:

A

Afghanistan = AFG
Algeria= TMC, ALG, ALR
Argentina= ANC, ARO, CTI (Claro), UFN (Movistar), PSN (Personal)
Aruba= ARU
Australia= XSA, OPP, OPS (Optus), VAU (Vodafone), TEL (Telus), HUT (Three/Vodafone)
Austria= AOM, DRE (3 Hutchinson), MAX (T-Mobile), MOB (A1), MOK, ONE (Orange), TRG (Telering), ATO

B

Bahrain = ARB
Baltic= SEB
Belarus= MTB, VEL
Belgium= BSE, BAE, PRO, XEB
Bangladesh= TML, ETR
Bosnia-Herzegovina= ERO, BHO, BHT (BH Telecom), TEB
Brazil= ZTO, BTA, BTM, TMR, ZTA (Claro), ZVV (Vivo), ZTM (TIM)
Bulgaria= CMF, GBL, MTE, MTL (MTL), OMX, PLX, VVT (VVT)

C

 Cambodia= RCG
Canada= BMC (Bell), RWC (Rogers), TLS (Telus), KDO (Koodo)
Chile= CHO, CHB, CHE (Entel PCS), CHL (Claro), CHT (Telefonica)
China= CHN, CMC, CUH, INT, M00, TEC, TIY
Colombia= CGU, COB, COL, COM
Costa Rica= ICE
Croatia= CRO, TRA, TWO, VIP
Cyprus= CYV
Czech= ETL, KBN, O2C, OSK, TMZ, VDC, XCS, XEZ

D

Denmark=  DTL
Dominican Rep.= CDR, TDR
Dominica= CST, DCN, DOR

E

Ecuador= BBR
Egypt= EGY
El Salvador= DGC, TBS

F

Finland= ELS, SAU
France= XEF, AUC, BOG, COR, DIX, FTM, NRJ, OFR, ORC, ORF, OXA*, SFR, UNI, VGF

G

Germany= DBT, DTM (T-Mobile), DUT, EPL (E-Plus), MAN, MBC, OXA*, VD2 (Vodafone), VIA (O2), XEG
Ghana= SPN
Greece= EUR, AOC, COS (Cosmote), CYO, GER, OXX*, TGR, VGR (Vodafone), ILO (HotMobile)
Guatemala= PCS

H

Hong Kong= TGY
Hungary= XEH, PAN (Telenor), VDH, WST, TMO,  TMH (T-Mobile)

I

India= INU, IND, INA, INS, IMS, REL
Indonesia= AXI, SAR, XSE
Iran= THR
Ireland= 3IE, VDI
Israel= CEL, PCL, PTR
Italy= FWB, GOM, HUI, ITV, OMN, OXA*, TIM, VOM, WIN, XET
Ivory Coast= IRS, SIE

J

Jamaica= JBS, JCN, JCW
Japan= DCM, SBM, VFK
Jordan= LEV

K

Kazakhstan= EST, KCL, KMB, KZK, OXE*, SKZ
Kenya= KEN, KEL
Korea= SKT

L

Libyan Arab Rep.= MMC
Lithuania= TLT
Luxembourg = LUX

M

Macao= VTN
Macedonia= TMC, MBM
Malaysia= CCM, FME, FMG, MXS, OLB*, XME
Mexico= SEM, TCE, TMM, UNE
Mongolia= MPC
Morocco= FWD, MAT, MED, MWD, SNI, WAN

N

Netherlands= BEN, KPN, MMO, ONL, QIC, TFT, TNL, VDF, VDP, XEN
New Zealand= VNZ
Nigeria= ECT, GCR, MML
Norway= TEN

P

Pakistan= PAK, WDC
Panama= BPC, PCW, PBS
Peru= PEB, PET, SAM
Philippines= FAM, GLB, OLB*, SMA, XTC, XTE
Poland= ERA, IDE, PLS, PRT, XEO, OXA*, OXX*
Portugal= OPT, OXX*, TCL, TMN, TPH, XEP
Puerto Rico= CEN, PCI, TPR

R

Romania= CNX, COA, HAT, ORO, OXX*
Russia= AZC, BLN, EMT, ERS, GEO, MTV, OXE*, SER, SNT

S

Saudi Arabia= JED
Serbia Montenegro= MSR, OXX*, PMN, SMO, TOP, TSR
Singapore= MM1, XSP, SIN (Singtel), STH (Starhub), BGD, XSO
Slovenia= MOT, SIM
Slovakia= GTL, IRD, ORS, OXX*, TMS
South Africa= XFAXFEOXX*, XFC, XFM, XFV (Vodafone)
South West Asia= SWA
Spain= FOP, AMN (Orange), ATL, EUS, XEC (Movistar), YOG (Yoigo)
Sweden= BAU, BCN, BME, BSG, BTH, COV, HTS, SEN, TET, TLA, TNO, VDS, XEE
Switzerland= AUT, MOZ, ORG, OXX*, SUN, SWC

T

Taiwan= BRI, CWT, TCC, TCI, TWM
Temporary= TEM
Thailand= CAT, OLB*, THE, THL, THO, THS
Tanzania= SOL
Tunesia= ABS, RNG
Turkey= TUR, BAS, KVK, TLP, TRC

U

Ukraine= KVR, SEK, UMC
United Arab Emirat= AFR, ARB, ITO, MID, OXE*, XSG
United Kingdom= BTU, EVR (EE), BTC, CPW (Carphone Warehouse), H3G, O2I, O2U (O2), ORA (Orange), OXA*, TMU (T-Mobile), TSC, VIR, VOD (Vodafone), XEU
USA= AWS, CLW, DOB, TMB, USC
Uzbekistan= UZB

V

Venezuela= VMT (Movistar), DGT, MVL
Vietnam= DNA, FPT, OLB*, PHU, SPT, TLC, VTC, VTL, XEV, XXV
Let us know if we have missed any.
* Multi CSC for couple of countries and regions (“O” refers to Open)