In which order do I have to work?

Back up, unlink, erase, hand over - in exactly that sequence. First move photos, histories, contacts and logins to a destination that belongs to you, and check on the new device that they arrived. Then sign the device out of the manufacturer account and remove it from the device list, unpair watches and headphones, remove payment cards and move your two-factor methods across. Only then do you reset. Finally, take out the SIM and memory cards and hand the device in. Skip the second step and you leave behind an activation lock that can only be released afterwards through the original account.

What is the activation lock and how do I get rid of it?

The activation lock is an anti-theft measure: after a reset the device asks on first start for the credentials of the account it was last signed in to. It sits with the manufacturer, not on the device, which is why it cannot be bypassed by a second reset or through recovery mode. The one clean route is to remove the device from the device list in the manufacturer account - which also works after the fact, as long as the original account holder can be reached. When buying used, therefore, ask to be shown before the handover that the setup assistant does not request an unfamiliar account.

What happens to the eSIM and the memory card?

Both are frequently not covered by the reset. The memory card is a storage medium in its own right: take it out and either keep it or format it on a computer. The SIM card should come out too, as it holds contacts and text messages. The eSIM, by contrast, sits inside the device and is tied to your mobile contract. It is transferred to the new device by your provider or explicitly deleted; a reset on its own does not reliably do that. Settle this before the handover, otherwise your contract stays attached to a device that is no longer yours.

Am I liable for defects in a private sale?

In principle a private seller is liable for material defects too, for used movable goods for two years from handover. Private individuals may, however, exclude that liability in the contract, and that is exactly what the usual wording in classified ads is for. The exclusion does not hold if a defect was fraudulently concealed: in that case the seller cannot rely on such an agreement. In practice that means fall damage, moisture, weak battery life and missing security updates belong in the ad. An open description with photos tends to fetch the better price and saves the argument after the sale.

Where does a device go that can no longer be sold?

Not into household waste. Distributors with a sales area for electrical equipment of at least 400 square metres have to take back old devices with no external dimension greater than 25 centimetres - free of charge and without any new purchase being required, limited to three old devices per device category. A phone meets that condition. Municipal recycling centres accept old devices as well. What matters is that you erase beforehand: the law expressly names the end user's own responsibility for deleting personal data. Swollen batteries should be reported separately at the collection point.

Selling your old phone: erase your data for good

In short and in plain language

Do you want to sell or give away your old phone? Then your data should not go with it. The article shows you how to do this.

The order matters. First you back up your data. Then you sign the phone out of your account. Only then do you reset it.

If you reset too early, you have a problem. The phone can stay locked for the buyer.

Also unlink your watch, headphones and payment cards from the phone. An old phone does not belong in the general waste.

We come to your home and go through it all with you.

The old phone stays in the drawer because it still works - and because erasing it feels like a chore to be dealt with some other day. That is how German households have accumulated 167 million unused mobile phones and smartphones (Bitkom), with 86 per cent of people in Germany keeping at least one such device at home (Bitkom). The second most common reason is not convenience but a well-founded worry: 28 per cent hold on to the old device because they fear personal data could fall into the wrong hands (Bitkom). That worry can be settled in barely half an hour. The catch lies less in the erasing itself than in the order of the steps. Reset the phone to factory settings first and try to sign out of the manufacturer account afterwards, and you end up holding a device whose storage is empty but which stays locked for the buyer. This guide therefore works through the process in the order that holds up in a real living room: back up, unlink, erase, hand over. It also explains what happens to a device that can no longer be sold, and which obligations fall on retailers and on private sellers.

Key takeaways

The order decides: back up, sign out of the account, reset, hand over. Reset without signing out and you leave behind an activation lock that makes the device worthless to the buyer.
A reset only counts as erasing if the storage was encrypted beforehand. The BSI therefore advises checking that a screen lock is set and encryption is active before you reset.
Unlinking involves more places than the manufacturer account: paired watches and headphones, stored payment cards, two-factor methods, eSIM profiles and permissions on your home network.
In a private sale, liability for defects can be excluded by agreement - but that exclusion does not hold if a defect was fraudulently concealed.
A device that can no longer be sold does not belong in household waste. Larger electronics retailers have to take small devices back even without a new purchase.

Why the old device stays in the drawer

The number of unused devices is falling, but slowly: from 195 million the previous year to 167 million (Bitkom). Asked for their reasons, 48 per cent name the wish to have a spare device for emergencies (Bitkom). Concern about data follows at 28 per cent, and 11 per cent simply do not know exactly where and how to hand an old device in (Bitkom). Among people over 65 that uncertainty is markedly more pronounced: 16 per cent of this age group do not know where the devices should go (Bitkom). Three very different hurdles, then - a practical one, a technical one and an organisational one. The practical one usually resolves itself once it becomes clear how little a four-year-old phone offers as an emergency device: the battery is weak, security updates have stopped, and in a real emergency you would first have to swap a SIM and sign in again. The technical and the organisational hurdle remain - and those are what this guide is about.

A spare phone in a drawer is not a backup

Many people keep the old phone assuming the photos are still safely on it. That holds only as long as the battery allows and as long as nobody mislays the device. Storage that has not seen a charger for years is not an archive you should rely on, and a single device meets none of the requirements of a proper backup. What a backup with two copies in two places looks like is described in Back up phone photos and data. Once that backup is in place, the old device loses its last job - and is free to go.

The order that makes the difference

Almost every mishap when passing a device on comes down to the same cause: the steps were taken in the wrong order. A factory reset erases the storage, but it does not release the tie to the manufacturer account. That tie is an anti-theft measure and it does exactly what it is designed to do: after the reset the device asks, on first start, for the credentials of the account it was last signed in to. For the buyer the device is unusable, and for the seller an awkward reversal begins in which they either have to reveal their account password to a stranger or take the device back. All of that is avoidable by taking the four steps in the right order. Each of them is harmless on its own; only their sequence turns four small tasks into a clean handover.

1. Back up

Move photos, messages, contacts, notes and logins to a destination that belongs to you - then check on the new device that they arrived.

2. Unlink

Sign out of the manufacturer account, lift the activation lock, and move paired devices, payment cards and two-factor methods across.

3. Erase

Check encryption, then reset to factory settings. On old devices, overwrite the free storage and reset a second time.

4. Hand over

Sell, give away or take it to a collection point - with cards removed, accessories included and an honest description of its condition.

Step 1: back up before anything disappears

The first step is the one you cannot catch up on later. After the reset the storage is empty, and whatever was not backed up beforehand is gone. In practice that means: do not rely on a feeling, check on the new device. The most common mistake is assuming that cloud storage has already taken care of everything - what it has usually taken care of is photos and contacts, but not message histories, not the voice messages inside them, not the notes of an app that keeps its data locally, and not the one-time codes of an authenticator app. What a complete move looks like is set out step by step in Moving your data to a new device. The list below is the short version of it, meant as a final check immediately before erasing.

Photos and videos: compare the image count on the old and the new device, not just the folder name.
Message histories: create a backup and restore it on the new device before the old one is erased.
Contacts and calendars: check whether they are tied to an account or held only on the device.
Authenticator apps for two-factor methods: move the accounts across individually - an ordinary backup does not cover them.
Notes, voice recordings, step data, documents in public-authority apps: go through locally stored items one by one.
Logins: move them into a password manager instead of leaving them in the old browser (Setting up a password manager).

Allow a week of overlap

Do not erase the old device on the same day the new one goes into service. Give yourself a week in which both devices still exist. During that week it reliably becomes obvious what is missing: the online banking login that had to be confirmed on the old phone, the rail card in an app, the photos from a shared album. As long as the old device is still signed in, all of that is a matter of minutes. Afterwards it turns into a hunt for recovery keys.

Step 2: release the device from the account

Unlinking is the step most often skipped, because it is invisible. A phone today is not a device but a node in a web of accounts, permissions and trust relationships. It is registered as a trusted device in the manufacturer account, it receives confirmation codes, it is paired with a watch and headphones, it holds payment cards, it has a permission on the home network, and in many cases it carries an eSIM profile that your mobile contract depends on. Each of these connections is released in its own place, and none of them disappears through a reset. The principle is therefore simple: while the device is still signed in, every one of those places is two taps away. Afterwards you are into recovery procedures, and those take days.

Sign out of the manufacturer account and then remove the device from the account device list. That is what lifts the activation lock.
Unpair connected devices: watch, fitness band, headphones, tablet, television, car. A watch still tied to the old account cannot be paired again later.
Remove stored payment cards from the payment app and detach the card from this device in your bank account.
Move two-factor methods to the new device - bank, email, public-authority access, online shops. Do this one first, otherwise you lock yourself out.
Have the eSIM profile transferred to the new device by your provider; take the physical SIM out and keep it.
Remove permissions on the home network and in smart home hubs so the old device has no way back in.
Tidy up linked access in public-authority and health apps - what to bear in mind is covered in The digital wallet: your ID moves to your phone.

The activation lock survives the reset

If a device is reset without being removed from the manufacturer account first, it will ask on first start for the credentials of exactly that account. A second reset does not help, and neither does a restart in recovery mode - the lock sits with the manufacturer, not on the device. The only way out is for the original account holder to remove the device from their device list after the fact. So when you buy a used phone, ask to see it switched on and freshly set up before you hand over any money. A device whose setup assistant asks for someone else's account is not handover-ready.

Step 3: erasing that deserves the name

A factory reset does not overwrite the storage cell by cell. With current technology it does not have to: the storage is encrypted, and the reset discards the key. What is left cannot be read without it. That effect, however, depends on a condition which the German Federal Office for Information Security spells out explicitly: the encryption has to have been active beforehand, and it is only active if a screen lock with a PIN, pattern or password was set (BSI). If you have used your phone for years without a lock, set a PIN first, wait for the encryption to complete and only then reset. For older devices that offer no encryption, the BSI recommends a second pass: reset, fill the free storage with large harmless files and reset once more. It is fiddly, but it takes a good half hour - and afterwards the old contents are, for practical purposes, no longer reassemblable.

Approach	What actually happens	Suitable for
Deleting files one by one	Only the reference disappears; the data stays in free storage.	nothing - this is not erasing
Reset without a prior screen lock	The storage is released, but it was unencrypted.	only with an overwriting pass afterwards
Reset with encryption active	The key is discarded and the remainder is unreadable.	phones and tablets of current design
Reset, overwrite, reset again	The free storage is occupied by new data.	older devices without encryption
Leaving the memory card in the device	The card is often not covered by the reset at all.	nothing - take the card out
Device broken, screen destroyed	No access, no erasing - the storage stays written.	return with removal of the storage medium

What regularly gets overlooked

The internal storage is not the only place where something stays behind. In practice, almost every follow-up question that reaches us after a sale falls into a handful of categories - and none of them concerns the internal storage. It is the small storage media and the outward links that get forgotten, because they do not show up on the screen. Tick off these six points and the rest is safely behind you. The effort involved is a few minutes, as long as the device is still signed in.

Memory card: it is a storage medium in its own right and is frequently skipped by the reset. Take it out, format it on a computer or keep it.
SIM card: it holds contacts and text messages, and in some tariffs the number assignment as well. Take it out before the device leaves the house.
eSIM: it sits in no slot but inside the device. The profile has to be moved or deleted at your provider, otherwise your contract stays attached to the old phone.
Paired accessories: headphones and watches store account data of their own and are hard to re-register after a messy handover.
Case and accessories: flip cases contain a surprising number of bank cards, notes with logins and passport photos. Look inside before you post it.
Accounts in services: giving the device away does not give an account away. Access nobody needs any more should be tidied up - which is what Digital legacy: putting online accounts in order is about.

The law names your own responsibility explicitly

The German Electrical and Electronic Equipment Act obliges public waste management authorities to inform private households, among other things, about the end user's own responsibility for deleting the personal data on the old devices being disposed of (ElektroG). Erasing is therefore expressly the business of whoever hands the device in - not of the collection point and not of the recycler. Drop an unerased device into a collection container and you hand your data in with it.

Selling, giving away, handing back

In a private sale, statutory liability for defects applies: for used movable goods the seller is liable in principle for two years from handover (BGB). Private individuals may exclude that liability in the contract, and the usual wording in classified ads aims at precisely that. The exclusion has a limit, though: a seller cannot rely on an agreement excluding or restricting the buyer's rights in respect of a defect insofar as the seller fraudulently concealed the defect (BGB). So if you know that the battery is flat after two hours, or that the device met moisture after a fall, write it in the ad. An honest description of the condition with photos of the scratches tends to fetch a better price than a flattering one - and it saves the argument after the handover. At the handover itself, note down the serial number, the fact that the device was passed on in a reset state and that no lock is active any more.

The one move that saves the most trouble

Before the handover, show the buyer the first setup screen of the reset device. If no unfamiliar account is requested there, you have proved that the activation lock is lifted. It takes thirty seconds and replaces every assurance in the ad text. For you it is at the same time the check on whether step two was really complete - because otherwise this lock only surfaces once the money has changed hands.

When the device is no longer sellable

Not every old device finds a buyer. A phone with a broken screen, no updates and a swollen battery belongs in the collection stream, not on the sales listing - and certainly not in household waste. Returning it is easier than the topic's reputation suggests. Distributors with a sales area for electrical and electronic equipment of at least 400 square metres are obliged to take devices back (ElektroG). Small old devices with no external dimension greater than 25 centimetres have to be taken back free of charge in the retail shop or in its immediate vicinity, expressly without any new purchase being required; this is limited to three old devices per device category (ElektroG). A phone falls below that limit in every dimension. Municipal recycling centres also accept old devices, and many network operators offer return routes by post.

That these routes get used is far from a given. The law sets a collection rate of at least 65 per cent of the average weight of the equipment placed on the market in the three preceding calendar years (ElektroG). In reporting year 2023 the collection rate reached 29.5 per cent - the target was clearly missed (Umweltbundesamt). What does get collected, on the other hand, is properly processed: according to preliminary results, just under 758,000 tonnes of waste electrical and electronic equipment were recycled in Germany in 2024 (Statistisches Bundesamt), and a further 17,600 tonnes were prepared for re-use (Statistisches Bundesamt). The recycling rate stood at 84.3 per cent and thus barely changed against the previous year (Statistisches Bundesamt). The bottleneck is therefore not in the processing but upstream of it: in the devices that do not set out on that route at all.

Check whether a repair is worthwhile. Since 2026 there are extended entitlements, which we summarised in The right to repair.
If not: back up the data and make the device handover-ready following steps one to three.
Take out the SIM card and the memory card, and have the eSIM profile released by your provider.
Report swollen or damaged batteries separately - they have to be handed in apart at the collection point.
Take the device to a collection point: a municipal recycling centre or an electronics retailer with a sales area from 400 square metres.

When the device can no longer be operated

A phone with a destroyed screen can no longer be reset - the storage stays written. Two routes remain: on some devices a reset from recovery mode via the volume keys works even without a picture. Otherwise the only options are to have the storage medium removed before handing the device in, or to use a collection point that confirms destruction. With soldered storage, mechanical destruction of the board is the last route left. In that situation, call us before you give the device away - we will look at whether the storage can still be read out and erased.

How we support you with this

The four steps are not difficult in themselves. What makes them tiring is that they happen in six different places, that each of those places goes by a different name, and that a forgotten item only surfaces weeks later. So we walk the route together with you - in your home, on your devices, at your pace. If a new device is being set up anyway, we bring the accessibility settings along; which ones those are is described in Making your phone easier to use. And if you are unsure whether everything really has been backed up, drop us a line - one question beforehand is cheaper than a recovery afterwards.

Erasing takes ten minutes. The half hour before it is the actual work - and it decides whether the device starts up for the buyer or ends as an expensive paperweight.

Technik daheim

Taking stock

We look at which accounts, cards and pairings are actually attached to the device - usually there are more of them than expected.

Backup with a check

We back up to a destination that belongs to you and verify on the new device that photos, histories and logins have arrived.

Erasing with proof

Check encryption, reset, overwrite on older devices - and look at the empty setup screen together.

Disposal settled

We tell you whether a sale is worth it and, on request, take the device to the collection point.

Sources and Studies

This article draws on a survey by the digital association Bitkom on unused mobile phones in German households, on recommendations from the German Federal Office for Information Security (BSI) on permanently deleting data, on figures from the German Environment Agency (Umweltbundesamt) and the Federal Statistical Office (Statistisches Bundesamt) on waste electronics, and on the German Electrical and Electronic Equipment Act (ElektroG) and the German Civil Code (BGB). The figures quoted refer to the state of the respective publication; the Bitkom survey is based on telephone interviews with 1,004 people in Germany aged 16 and over.

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