If you don't want your Apple device to automatically rejoin a network, you can make it forget that network.
Your Apple device remembers each Wi-Fi network that you joined on that device, and it automatically joins that network again whenever it's in range. If you don't want it to rejoin the network, or you want it to join with a different password, follow these steps to make your device forget that network and its password.
Forget a network on your iPhone, iPad, or iPod touch
- Go to Settings > Wi-Fi.
- Tap next to the Wi-Fi network that you want your device to forget.
- Tap Forget This Network, then tap Forget to confirm.
Forget a network on your Mac
- Choose Apple menu > System Preferences, then click Network.
- Select Wi-Fi in the list on the left.
- Click the Advanced button.
- The Wi-Fi pane shows a Preferred Networks list. Select the Wi-Fi network that you want your Mac to forget.
- Click the remove button (–) beneath the list. If you're asked to confirm, click Remove.
- Click OK.
- Click Apply.
- If you're using a supervised device that manages the connection to the Wi-Fi network, you might not have the option to forget that network.
- As an alternative to forgetting a network on your device, you can turn off Auto-Join for that network. Your device will still remember the network and its password, but will not attempt to join it automatically.
- On your Mac, you can also drag the network to a lower position in the Preferred Networks list. If another network in the list is available at the same time, your Mac will attempt to join that network before any network that appears later in the list.