[Samsung Galaxy S23 Ultra] butchieboy:
Most of us already know how to flash firmware with Odin. Here, anyone can post available firmware for everyone to use as well as general discussion.

U firmware can be flashed on a U1 device and U1 firmware can be flashed on a U device using Odin. Most times going between the 2 requires you to factory reset.

Make sure you have the latest Odin installed on your computer. Download the correct firmware for your device (SamFw) is a good place to find firmware. After firmware is downloaded, you will need to extract the firmware. Once extracted you will have files BL..AP..CP..CSC..and HOME_CSC

You should already have started a basic setup of your device. Once you have done that go to Settings/About phone/Software information/Build number. Click build number about 8 times to activate Developer Options. Go to Developer options and toggle on USB debugging. Power off Boot device to Download mode, open Odin on computer, connect device and ensure Odin detects device. Once detected, add BL file to BL spot in odin, AP file to AP and so on. Remember flash just CSC will wipe device, using HOME_CSC will keep data. Once all files have been added in correct spots in Odin click start. Sometimes Odin flash does fail. Just start over doing the same steps again. It should be noted that if you do get the blue emergency download screen you are still able to flash the firmware from this screen.

If there is anything that I have forgotten feel free to pass it along. This is a user friendly thread. Huge thanks to:

Mohammad, JrKruse, Klabit, Mark, and anyone else I forgot to mention for helping me continue to learn.

LOCKED FIRMWARE (U)

SM-S918USQU1AVKT Locked (U) USC

File on MEGA

mega.nz

Firmware S918USQU1AWA6

Link: https://www.androidfilehost.com/?fid=4279422670115718584

ATT/CCT/CHA/DSH/TMB/TMK/USC/VZW

Firmware S918USQU1AWBD

https://mega.nz/file/eh5XVJBb#_tpvdP8mipVBXzrxKMVgX6FqsZO5LhLRqy4w5Y4f8F0 CHA/CCT/VZW

Firmware S918USQU1AWBE

https://mega.nz/file/iwxWkT4Q#vUn46LmIeRsEW5x6Q6NxyhmZZyTqTVrervj0kLGm-Sw ATT/DSA/DSH/TMB/TMX

Firmware S918USQS1AWBM (MARCH SECURITY PATCH)

https://mega.nz/file/6wxXFZja#T7WFvfkcF18BPsRXDUt_GguEzaclcPs7NGCPr5z4jvw ATT/TMK/TMB/DSH

Firmware S918USQS1AWBL (MARCH SECURITY PATCH)

https://mega.nz/file/ax4TXKhS#PmNlyWPw_SAE4rya03dtGUV8NJSwmUZLllMUbqDhOHs VZW/CHA/CCT

Firmware S918USQU1AWC8 April Patch

https://mega.nz/file/P5BS1AIT#uMox4syuyluA21zlJl0N8Z7A8kEE-C11Llw_kDxOlfg

ATT/DSA/DSH/TMB/TMK

AT&T SM-S918USQS1AWC9 May Update Link https://www.androidfilehost.com/?fid=10620683726822051051 (Thanks Venom)

UNLOCKED FIRMWARE (U1)

S918U1UEU1AWA6 Unlocked Firmware January Patch Link: https://www.androidfilehost.com/?fid=4279422670115718950 (Thanks Venom)

SM-S918U1UEU1AWBE Link: https://www.androidfilehost.com/?fid=4279422670115722421(Thanks Venom)

TMB-S918U1UES1AWBM Firmware March Patch

https://mega.nz/file/HlQnXD6S#vx6biL_MLlf85ng0IPKpH6TUd8ZlorLPskGTub4SfZ8

S918U1UEU1AWC8 Firmware April Patch Link

https://mega.nz/file/XwZHXbra#eGWTIHJYg6GnkRbj_6l8S_wuzMhUUowgD54zc6tc_hg

USERDATA

USERDATA_ATT_S918USQU1AWBE https://www.androidfilehost.com/?fid=4279422670115724049 (Thanks Venom)

USERDATA_ATT_S918USQU1AWC8 Link: https://www.androidfilehost.com/?fid=4279422670115734919 (Thanks Venom)

TMOBILE USERDATA https://drive.google.com/file/d/1jMWFbpKxnlBANPdd-8KDzZnj6_Te6DN6/view (Thanks iBowToAndroid)