Aqara has officially launched its Smart Lock U400 in Australia following its debut at CES last week, bringing ultra-wideband technology to residential access control for the first time. The Matter-certified lock represents a significant shift in how smart locks detect and authenticate users at the door.
The U400 uses UWB positioning to enable automatic unlocking as authorised users approach their front door with an iPhone or Apple Watch. Unlike Bluetooth-based proximity systems that rely on signal strength, UWB calculates precise distance and angle using Time of Flight measurements and Angle of Arrival data. This means the lock can differentiate between someone approaching from outside versus walking past on the inside, reducing false unlocks.
The lock works with home keys stored in Apple Wallet, allowing entry without pulling out a device. An iPhone in a bag or pocket will trigger the unlock sequence, as will an Apple Watch worn on the wrist. The UWB implementation includes scrambled timestamp sequence protection, which helps prevent relay attacks where signals are intercepted and retransmitted by unauthorised parties.
For users who prefer alternative methods, the U400 supports multiple access options. NFC unlocking works with home keys or Aqara’s dedicated NFC cards, while the integrated fingerprint sensor provides biometric access. The lock accepts both one-time and recurring passcodes, connects to voice assistants including Alexa and Siri, and includes a mechanical key backup for power failures or system issues.
The U400 runs on Thread protocol and supports Matter connectivity across platforms like Alexa, Apple Home, Google Home, Home Assistant, and SmartThings without needing a proprietary hub. The lock is Aliro-ready, positioning it for broader mobile access compatibility. Samsung Wallet support is scheduled for Q1 2026, extending digital key functionality to compatible Samsung devices.
Additional features include gyroscope-powered auto-locking that engages after the door closes, IP65 weather resistance for outdoor installation, and a rechargeable lithium-ion battery rated for six months per charge under typical use. When the battery runs flat, users can recharge it using a standard USB power bank. The lock comes in four finishes: Black, Silver, Shadow Black, and Satin Nickel.
The Aqara Smart Lock U400 with M100 Kit starts pre-orders in Australia on Friday 16 January at $399 AUD through the Aqara Official Store. This early bird price runs until 17 February, with deliveries starting in early February. Standard retail pricing is set at $549 AUD, making the pre-order offer a 27% discount. The U400 without the hub is also stocked at select Apple Stores and available through Apple’s online store.
