Two Xbox Live Accounts on One Xbox 360: Not Possible

No. The Xbox 360 OS supports only one active Xbox Live profile at a time. Simultaneous dual-account online play on a single console is impossible.

Hard Limitations

• Single Sign-In Architecture: The 360's kernel only maintains one live Xbox Live session
• Split-Screen Online Blocked: Even in games supporting local split-screen (Halo 3, CoD, Gears), only the primary signed-in profile connects to Xbox Live. Guest profiles are strictly offline
• No Profile Switching Mid-Game: You cannot hot-swap profiles during a session

Workarounds

• Second Console: Each player needs own console + Gold subscription for online co-op
• Local Multiplayer Only: Split-screen/system link (LAN) works offline. No Gold required for System Link
• Upgrade to Xbox One/Series X|S: These support "Home Gold" sharing and multiple simultaneous sign-ins. Xbox 360 does not

This limitation is hardcoded in the Xbox 360 OS. No hack, update, or workaround enables dual Gold sign-in on one 360.