When you are done with the burner phone, make sure that you get rid of it in a thoughtful way as well. “At the end of the intended use, consider steps to eliminate information, remove SIM cards and/or memory cards, making sure not to leave a potential vulnerability after you,” says Access Now’s Al-Maskati.

Using an Alternative Phone

Depending on your risk model, it may not be appropriate or even the most practical to use a true burner phone. Instead, you may want to consider using an altphone to separate elements of your digital life.

“There is a lot of confusion, because ‘burner phone’ is a generic term,” says Matt Mitchell, CEO of the risk mitigation firm Safety Sync Group. “I usually try to group tactics and advice based on goals. It begins with why a normal phone isn’t good for privacy and then a dial on how private you’re trying to get. The privacy goals are the dial—from safer hygiene, to more secure operating systems, to straight-up locked-down phones.”

For many people, an altphone or “lighter” burner phone is likely to be a smartphone that allows a wide range of communications and access to privacy-enhancing tools such as encrypted messaging apps like Signal, VPNs, online tracker blockers, and more. This way you can tune your personal privacy dial to keep certain web browsing, software use, media consumption, or communication more private and anonymous than it would be on your normal devices.

“What are you trying to protect? If you’re just trying to obscure your phone number from somebody, you can do that in a much lighter way” than using a heavily anonymized device, the ACLU’s Williams says. “But if you’re really trying to go off grid, you have to do all this other stuff.

An altphone may be a smartphone that you separate as much as possible from your identity, perhaps a phone that you only use for attending protests. Or it could be an old phone you repurpose and use for things like traveling. How you set the privacy dial depends on the use case.

“A repurposed phone can be used for an extended period of time,” Cyberlixir’s Vo says. “A repurposed phone already has your traces, even with factory reset. There might be a sales receipt, CCTV log, or someone taking a picture of you talking on the phone. So they are useful for compartmentalizing activities. Work versus personal phone is the most obvious example. Or one for international travel.” Reused devices also retain certain identifiers such as IMEI numbers over time.

Using a smartphone as a second device does have its own considerations. When it comes to mainstream devices, “smartphones do a terrible job at protecting people’s privacy and securing their communications,” says Access Now’s Al-Maskati. “If people obtain a smartphone to use as a burner, it’s best to reset to factory settings, never connect any real accounts (AppleID, Google, social media), and do not sync any other information, as well as disabling unnecessary location and other services.”

You should only use your altphone for its intended purpose—if it’s a phone you want to take to protests, for example, it shouldn’t be used for texting friends or online shopping. As with a true burner phone, you should avoid using it in the same location that you use other devices—in other words, avoid connecting to the same Wi-Fi networks. Don’t turn your altphone on alongside your day-to-day devices and, relatedly, don’t carry them all together unless your altphone is in a Faraday bag. Only provide contact information for the altphone to those who need it.

Whether you’re using a burner phone or an altphone, though, the bottom line is that there are no guarantees or perfect solutions. And if there is absolutely no room for error, go analogue and don’t bring or involve a phone in whatever you’re doing.