BYD Dolphin Smart Key and App: Every Remote Function
Share
The BYD Dolphin gives you three ways to access and control it. The smart key handles locking, unlocking, the trunk, remote start, lowering the windows, and remote A/C. The NFC key card is a slim backup key for locking, unlocking, and starting. The BYD app lets you switch on the A/C, lock or unlock, and check the car from your phone. Each method suits a different moment.
Key, Card and App: What Each Can Do
| Function | Smart Key | NFC Card | BYD App |
|---|---|---|---|
| Lock and unlock doors | Yes | Yes | Yes |
| Open the trunk | Yes, double-press | No | Varies by app |
| Remote start | Yes | No | Varies by app |
| Lower the windows | Yes, hold unlock | No | No |
| Remote A/C | Yes | No | Yes |
| Locate the vehicle | Yes | No | Varies by app |
| Works without phone signal | Yes | Yes | No |
The Smart Key: Your Main Remote
The smart key is the everyday tool for controlling your Dolphin, and it does more than most owners realise. Its buttons cover lock, unlock, trunk, and remote start, with a mechanical key hidden inside as a backup.
- Lock and unlock: Press to lock or unlock all doors, with the turn signals flashing twice on unlocking
- Open the trunk: Double-press the trunk release button, and the signals flash twice
- Lower the windows: Press and hold the unlock button to lower all four windows, handy for venting a hot cabin
- Find your car: The remote can help you locate the vehicle in a busy car park
One quirk from the manual: holding the lock or unlock button does not repeat the action. You need to release and press again.
Remote Start From the Smart Key
The Dolphin can be started remotely from the smart key, which is useful for getting the climate going before you get in.
- Check the conditions: The car must be off, in Park, and stationary
- Press and hold: Hold the remote start button for two seconds to start the car, with the signals flashing three times
- It waits for you: If there is no valid operation within 10 minutes, the car powers off automatically
- To stop: Press and hold the button again for two seconds to power off
The NFC Card: Your Slim Backup
The NFC key card is a credit-card-sized backup that fits in a wallet. It is perfect for when you would rather not carry the fob, or if the smart key battery goes flat.
You use it by holding it against the NFC mark on the driver's side mirror for a second or two, which locks or unlocks the car. After unlocking, you have a short window to start driving. It is a backup key rather than a remote, so it does not offer functions like remote A/C.
For the full setup and use, see our dedicated BYD Dolphin NFC key card guide, which covers exactly where to tap and how it works.
The BYD App: Control From Your Phone
The BYD app, known as the BYD Cloud Service app, extends control to your phone over the internet. It is the method for when you are away from the car.
- Remote A/C: The manual confirms you can switch on the air conditioning from the app to pre-cool or pre-warm the cabin
- Lock and unlock: Manage the doors remotely from your phone
- Vehicle status: Check information like charge level and, on most versions, the car's location
- Notifications: Receive alerts, including child presence detection warnings
The exact features depend on your app version and market, so treat the app's own menus as the definitive list. What the manual confirms is remote A/C and remote door control.
Remote A/C: Pre-Cool or Pre-Warm
Remote A/C is one of the most loved features, and the Dolphin gives you two ways to use it. You can switch on the air conditioning using either the smart key or the BYD app, so the cabin is comfortable before you get in.
One practical note from the manual: the system may not be able to switch on the A/C if the battery is low, so keeping a healthy state of charge is recommended if you rely on this feature.

Which Method Should You Use?
Each access method has its moment, and together they cover every situation.
- Everyday driving: The smart key, for full control at the car
- Travelling light: The NFC card, tucked in a wallet as a backup
- Flat key battery: The NFC card or the app keeps you moving
- Away from the car: The app, for remote A/C and checking status
- Cold or hot morning: Remote A/C from the key or app before you leave
The App Across the BYD Range
The BYD app works across the brand's models, with a consistent feel. If you drive more than one, these guides help you get the most from it.
- Our guide to the BYD app and its remote functions covers the app in detail
- The BYD app guide for the Atto 3 shows the app on the SUV