- U2 (easyJet)
- UA (United Airlines)
- U Fare
- uID
- Unaccompanied Minor (UM / UNMR)
- Unicorn Redemption
- United Club (UC)
- United Express (UAX)
- Upgrade Amnesia
- Upgrade Delusion
- Upgrade for Cash (UFC)
- Upgrade Grief
- Upgrade Hallucination
- Upgrade Hunter
- Upgrade Inventory
- Upgrade List
- Upgrade Math
- Upgrade Optimizer
- Upgrade Roulette
- UR Portal
