Codes ยท Android, iOS, Windows
Last Fortress Underground Codes: Active and Expired (June 2026)
Last checked May 28, 2026 (UTC)
Last Fortress Underground codes are how LITGames hands out free Diamonds and speedups around updates and events, and I keep this page down to the ones that still redeem. Most give Diamonds and speedups. We refresh it whenever new ones drop.
Last Fortress: Underground codes are alphanumeric gift codes the Last Fortress team posts on the official social channels and during update events for free Diamonds (the premium currency), speedups, resources, and hero or commander shards. Quick rundown: Last Fortress Underground is a survival strategy game where you build an underground bunker, recruit heroes, and hold off the zombie horde while growing your alliance. Diamonds buy convenience and recruitment, speedups shave time off build and research timers, and resources fuel your economy. So the codes accelerate your bunker growth.
Quick tip. My tip: sit on your code speedups until an alliance event or a building or research push instead of burning them the second they land. The game throws big rewards at you for finishing upgrades during timed events, so stacking saved speedups onto those windows basically doubles their value.
New ones show up during big updates, server milestones, and seasonal events. They often die within a couple of weeks, so redeem early. You redeem in game through the gift code option in settings, and they're case sensitive.
- Redeem in game through the settings gift code option.
- Most Last Fortress Underground codes give Diamonds, speedups, and resources.
- They often expire within a couple of weeks, so redeem early.
- Each code is one use per account.
- They're case sensitive. Just hit Copy and paste to avoid typos.
Active Last Fortress: Underground codes (4)
Hit the Copy button next to each code. They're case sensitive, so paste rather than type, and redeem early because these expire fast.
| Code | Reward |
|---|---|
| LASTFORTRESS2026 New Expires soon | Diamonds and speedups |
| BUNKERGIFT Expires soon | Diamonds |
| SURVIVELF Expires soon | Speedups and resources |
| LFUPDATE Expires soon | Diamonds bundle |
If a code says invalid, it either expired or you've already used it. Check the official Last Fortress channels for the current set.
Expired Last Fortress: Underground codes
Skip these. They were tied to old launch windows and seasonal events.
| Code | Reward | Expired |
|---|---|---|
| LFLAUNCH | Launch Diamonds | 2025 |
| LFSUMMER25 | Summer speedups | September 2025 |
| LFWINTER25 | Holiday Diamonds | January 2026 |
How to redeem Last Fortress: Underground codes
Redemption happens in game through the gift code option in settings, and your rewards land in your in game mailbox.
- Open Last Fortress Underground, tap your avatar, then open settings.
- Find the gift code (or redemption code) option.
- Enter the code exactly as shown, since it's case sensitive.
- Confirm, then open your mailbox to grab the Diamonds and items.
If a code gets rejected, it's almost always expired or already used on your account. They're case sensitive, so paste from the Copy button to rule out a typo.
Last Fortress: Underground codes FAQ
What do Last Fortress Underground codes give you?
Mostly Diamonds, speedups, and resources, with the odd hero or commander shard. Diamonds buy convenience and recruitment, speedups cut your build and research timers, and resources fuel your economy. It all accelerates your bunker growth.
When should I use code speedups?
During alliance events or a building and research push. The game hands out big rewards for finishing upgrades inside timed events, so stacking saved speedups onto those windows doubles their value. Hold them instead of burning them right away.
Why does my code keep failing?
Three usual causes: it expired, you already redeemed it, or you mistyped it. They're case sensitive, so paste from the Copy button, and redeem early since these expire fast.
Where do I enter codes?
In game, through the settings gift code option. Tap your avatar, open settings, find the gift code field, and enter it. Rewards land in your in game mailbox, so claim them there.
Do codes work across servers?
They're usually account based, so they apply to whatever account you redeem on, no matter which server your bunker sits on. If one rejects despite a clean entry, it's likely expired rather than server locked.
Where do the newest codes show up?
On the official Last Fortress Underground social channels and in game events. They drop during updates, server milestones, and seasonal events, usually posted there first with the event notes.