Are the previous owner’s data really deleted from a refurbished device?

At Revendo, yes - and it can be verified. Every device is erased using Phonecheck, software specialized in device refurbishment. Each individual erasure generates a signed certificate linked to the serial number of that specific device. “We erased it” thus becomes a record containing the device, time, and method.

Phonecheck follows NIST SP 800-88 Rev. 2, the currently valid US guideline for data erasure, as well as IEEE 2883, and is ADISA-certified.

Isn’t a factory reset enough?

Technically, yes, with one limitation. Modern iPhones and Android devices automatically encrypt all data. A factory reset deletes the associated key. Without the key, any remaining data on the storage is unreadable. This process is called cryptographic erasure, or Crypto Erase in English, and is explicitly recognized in NIST SP 800-88 Rev. 2 as an independent sanitization technique, including after the guideline’s fundamental revision in 2025.

What is missing is proof. No log, no serial number, no timestamp. For a personal device, that is sufficient. For resale by a company, it is not: Without documentation, it is not possible to show later that this exact device was actually erased at a specific time.

That is why our process combines two levels: your own reset as a prerequisite, and our certified erasure as additional proof.

What happens to my data when I sell my iPhone to Revendo?

The first level directly concerns you, and it is often overlooked: Your device must already be reset and must no longer have an active lock. For personal devices, this means no iCloud or Find My lock. For company devices, it means no active management through MDM, ABM, or JAMF. This applies equally whether you send the device by post or bring it to a Store.

We cannot buy a locked device. An active iCloud, Find My, or MDM lock can only be removed by the account holder, not by us, and that will remain the case: We never ask for login details and would not accept them. Therefore, buying a locked device is not possible regardless of its model or condition. If the lock cannot be removed, you are still welcome to leave the device with us. It will not be resold, but will instead be professionally recycled.

The next two sections explain how to get your device into this state and what to keep in mind.

What is the one-hour security delay about?

Since iOS 17.3, there has been Stolen Device Protection. If it is active, which is now the normal case, and your iPhone is not in a registered familiar location such as your home or workplace, security-related steps such as signing out of your Apple Account or turning off Find My require a security delay: Face ID or Touch ID confirmation, a one-hour waiting period, and then a second confirmation.

This only affects the iPhone, not iPad, Mac, or Apple Watch. In practice, this means that if you sign out of your Apple Account at our Store, that single step alone can take up to an hour. Whenever possible, do it at home, where the location counts as familiar and the delay does not apply. The next section explains how to prepare your device in detail.

How do I erase my device myself before selling it?

For the purchase to go through, the device must arrive with us reset and unlocked. Proceed as follows, depending on the device.

iPhone and iPad: There are two options, depending on whether you want to keep the content. If you want a backup, tap your name at the top of Settings, select “iCloud Backup” and “Back Up Now,” or connect the device to a Mac or PC using a cable and back it up through Finder or iTunes, respectively. If you want to transfer the content directly to a new device instead, without using a backup, use “Quick Start” or “Transfer from iPhone” when setting up the new device. Here’s how direct transfer works. Once your device is ready, tap your name at the top of Settings, scroll down, and sign out of your Apple Account, preferably at home because of the security delay mentioned above. This removes the Activation Lock. Finally, under “General” and “Transfer or Reset,” erase all content and settings.

Apple Watch: Unpair the watch in the Watch app on the paired iPhone. This automatically creates a backup, removes the Activation Lock, and resets the Watch, so no separate reset step is needed.

Mac: In System Settings, select “Transfer or Reset” under “General,” then choose “Erase All Content and Settings.” On older systems without this option, manually sign out of iCloud, iMessage, and your Apple Account, then reinstall macOS using the recovery system.

If something does not work because you do not have the password or the device no longer starts, contact us via our help page or ask at a Store. Depending on capacity, we can provide support on site, but this cannot be scheduled in advance. Detailed instructions are also available directly from Apple and Google. You can find our own overview here.

Once your device has arrived with us in this condition, the second level begins: our own erasure process.

What happens once Revendo has your device?

Erasing with Phonecheck is our first work step, before price evaluation and registration, regardless of whether you hand in the device at a Store or send it to us.

And then the key point: A device cannot be marked as “tested and ready for sale” in our system if no erasure certificate, dated no more than five days earlier, is stored. This is not merely a guideline everyone is expected to follow; it is built directly into the system, regardless of how busy things are.

This is complemented by the four-eyes principle: Every device is inspected by at least two people before it is approved. MATT, our testing robot, also provides support during the technical functional test: It performs the same tests as the inspection team, according to the same protocol, regardless of how busy things are. It supplements the human inspection; it does not replace it. We describe how MATT works here.

Does this apply to all devices?

No, and we would rather say that ourselves. Certified erasure with Phonecheck is used for iPhones, Android devices, iPads, and Apple Watch. We are in the middle of rolling it out for Macs, but it is not yet available in all Stores.

That does not mean Macs go on to the next stage unchecked. They are erased and undergo the same two-step inspection as every other device. What is still missing at some locations is the automatically generated certificate as additional proof. We would have preferred to have this everywhere already. We are stating it because it is part of the picture.

How can you recognize a refurbisher that takes it seriously?

This level of detail can be generalized. Refurbished is not a protected term. It appears on devices that have gone through industrial refurbishment and on devices that someone has briefly wiped clean. Three questions distinguish one from the other. We answer them here for ourselves because they should apply to every provider, including us.

First: Is there proof of erasure for each device, or only a general statement on the website? With us, there is one signed certificate per serial number, not a blanket statement.

Second: Does the system prevent the error, or does it rely on people? With us, a device cannot technically be approved without a valid erasure certificate, in addition to the four-eyes principle. This is built into the system, not just written in a work instruction.

Third: How precisely can a device be traced? With us, down to the serial number, from receipt through sale and throughout the entire refurbishment process.

When buying privately through a classified ad, this documentation is not available. That is not an argument against private sales; it is simply a difference you should know about.

In short

Whether a device may be sold by us does not depend on trust, but on two levels: your own reset as a prerequisite, and our certificate, which may be no more than five days old, as additional proof. That is the difference between a promise and a mechanism. At Revendo, the process begins as soon as your device arrives with us free of locks. After that, erasure is the first step, proof is mandatory, and without it a device cannot move any further through the system. We are not yet at this stage everywhere for Macs, and that is part of the picture too.

If you experience something different, tell us directly. Criticism helps us most where we can respond to it.

Is your old device still lying in a drawer? It will become neither more valuable nor safer there.

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