How to keep Bluetooth disabled at startup on Linux

On some Linux distributions, Bluetooth adapters automatically power on at system startup even when you set AutoEnable=false in /etc/bluetooth/main.conf. Desktop helpers like Blueberry or the default rfkill state restore can override that setting.

A reliable way to ensure the adapter remains off is to override the Bluetooth systemd unit and force a block after the service starts.

Create a systemd override file:

sudo mkdir -p /etc/systemd/system/bluetooth.service.d
echo -e "[Service]\nExecStartPost=/usr/bin/rfkill block bluetooth" | \
  sudo tee /etc/systemd/system/bluetooth.service.d/override.conf

Reload systemd and restart the service:

sudo systemctl daemon-reload
sudo systemctl restart bluetooth

Now the adapter will remain soft-blocked after every boot. You can still enable it manually at any time with:

rfkill unblock bluetooth

This approach works across Fedora, Ubuntu, and other systemd-based distributions, and avoids desktop tools automatically turning the adapter back on.