Introduction: we share more data than furniture
When a shared life ends, the material inventory is painful but finite. The sofa goes one way, the coffee machine the other, and the matter is settled in an afternoon. The digital inventory, by contrast, has no natural end: it keeps running on its own, silently, for years.
A "family" mobile plan taken out in 2021 keeps sending an itemised bill — with the list of numbers called — to an address that is no longer yours. Location sharing switched on one evening on holiday keeps reporting your daily movements. A streaming account shows your former partner what you watched last night at 11 p.m. A recovery email address, set up when everything was fine, still allows a password reset on your main mailbox.
This guide is not about feelings. It is about architecture: which technical dependencies two people create by living together, in what order to undo them, and how to do so without triggering a conflict or locking yourself out of your own accounts. With some nuances, it applies just as well to a flatshare coming to an end, a house move, or the end of a business relationship.
The diagnosis: mapping the points of contact
Before cutting anything, you need to know what exists. Most people massively underestimate the number of links created. Take a sheet of paper — not a document in a shared cloud, an actual sheet of paper — and work through these six families.
1. The communication infrastructure
- The mobile plan: a single account holder with several lines, or separate lines? Who receives the itemised bill? In France, the bill for a shared plan can show the numbers called and the volumes used.
- The internet router: the contract holder has access to the customer area, and therefore sometimes to devices' connection history, parental controls and network settings.
- The phone number: is it the recovery identifier for your accounts? With how many services?
- Email addresses: is there a joint mailbox? A redirected alias? A cross-linked backup address?
2. Platform accounts
Family accounts on Apple, Google, Microsoft, Amazon, Netflix, Spotify. "Family sharing" is an elastic notion: depending on the service, it grants access to purchases, payment methods, history and sometimes device location.
3. Location
Location sharing in messaging apps, Apple's or Google's "Find My" features, route-tracking apps, smartwatches, Bluetooth trackers slipped into a bag or a car.
4. The home's connected devices
Smart lock, video doorbell, indoor camera, thermostat, a vacuum cleaner that maps the rooms, voice speakers. These devices often remain linked to the account of the person who installed them, even after that person has moved out.
5. The financial and administrative ecosystem
Joint account, payment methods saved on platforms, subscriptions taken by direct debit, insurance policies, health cover, personal online portals with authorised beneficiaries.
6. Stored traces
Passwords saved in a shared browser, sessions left open on a shared computer, cross-linked backups, photos synced to a shared album.
A methodological rule: treat every line of this list as a door. A door is not closed because you no longer walk through it — it is closed when the lock has been changed.
The order of operations: from the most structural to the most visible
The classic mistake is to start with symbolic actions — removing a profile picture, leaving a group chat — which are noisy and improve nothing. Here is the reverse order.
Step 1: secure the main email address
Everything starts there. Your main mailbox is the master key: it allows almost everything else to be reset. In this order:
- Change the password to one that is long, unique and never reused.
- Check and delete any recovery addresses and numbers that are not yours.
- Open the list of active sessions and connected devices, and sign out of anything you do not recognise.
- Check that there are no automatic forwarding rules — a discreet filter that copies certain messages to another mailbox is undetectable in daily use.
- Enable two-factor authentication that does not depend on a shared device.
On this last point, if your second factor currently relies on an SMS received on a line you do not hold, the gap is wide open. A FIDO2 USB-C security key, or an authentication app installed on your phone alone, settles the matter. The physical key has the advantage of being inaccessible remotely: nobody can "transfer" it without your knowledge.
Step 2: take back control of the phone number
The mobile number has, in France as elsewhere, become a de facto civil identifier. Two cases:
- You are the line holder: good. Change the password for the operator's customer area, remove any authorised persons, and switch off delegated management options.
- You are not: request that your number be ported to a contract in your own name (in France the RIO code is obtained by dialling 3179). As long as you are not the holder, the contract holder can view the billing, cancel the line, or request a duplicate SIM card.
The second case deserves a clear decision. A number kept at the price of a contractual dependency is not really your number.
Step 3: cut off location sharing, methodically
Location sharing is the most frequently forgotten point, because it is invisible unless you go looking for it. Review:
- Apple and Google family sharing (locating members);
- "Permanent" shares in messaging apps;
- Fitness apps whose routes are public by default;
- Bluetooth trackers: Android and iOS now alert you when an unknown tracker is travelling with you, but the alert is not immediate. A GPS tracker and bug detector can remove any doubt about a vehicle or a bag, if the context warrants it.
Step 4: untangle platform accounts
Leaving a "family sharing" group does not erase the history already collected, but it stops the bleeding. Points to watch:
- Linked purchases: on some platforms, leaving a family group means losing access to content bought by the other person. Anticipate rather than find out afterwards.
- Saved payment methods: remove your card from accounts you no longer use, and vice versa.
- Subscriptions: list the recurring direct debits over three months of statements. It is the only reliable inventory.
Step 5: reclaim the connected home
If you are staying in the home, any device set up on the other person's account must be reset to factory settings and re-paired, not simply "removed from the list". This applies particularly to locks, doorbells and cameras. If you are the one leaving, do the opposite: remove your devices from your accounts before leaving them behind.
Also change the router's administrator password and the Wi-Fi password. A home network whose key is still circulating allows someone, at the very least, to see which devices are present and at what time.
Step 6: clean up shared machines
On a shared computer, create a separate user session or, better still, stop using it for sensitive exchanges. Check the passwords saved in the browser, synced profiles and automatic photo backups. A standalone password manager, with a separate vault per person, is a far better option than the browser's memory — and a paper password notebook, kept out of sight, remains an acceptable solution for backup codes you do not want stored online anywhere.
When the situation is tense
Everything above assumes a civil separation. That is not always the case. Where there is a context of control, harassment or violence, the logic changes: discretion takes priority over thoroughness, and the order of operations may be reversed.
A few principles recognised by specialist organisations and echoed by France's CNIL in its resources on cyber-harassment:
- Do not raise the alarm too early. Abruptly cutting off every form of access signals that you have understood. Depending on the situation, it may be preferable to prepare a complete switch (new account, new device, new number) and change everything at once.
- Document before deleting. Time-stamped screenshots, messages, statements: if you file a complaint, deleted evidence cannot be recovered. Keep it off the device concerned, on a hardware-encrypted USB stick stored elsewhere.
- Beware of spyware. Stalkerware installed on a phone the other person has had physical access to reports back messages, location and keystrokes. The Coalition Against Stalkerware and, in France, victim support organisations document the signs: battery draining fast, unusual heat, unknown device administration apps. If you have serious doubts, a factory reset — followed by manual reinstallation, without restoring the backup — is the only reliable answer.
- Set up an exit channel. To contact a support organisation, a lawyer or a friend without the call appearing on an itemised bill, sending a message with a hidden sender from a browser, or using a second phone unconnected to your identity, offers a discreet first step. A basic mobile phone rather than a smartphone, paid for in cash, remains the most low-key tool for this role: no account, no syncing, no history.
In France, 3919 (Violences Femmes Info) is anonymous and free, and does not appear on the itemised bills of most operators. 116 006 (France Victimes) supports all victims of criminal offences.
What remains, and what can be erased
Even after a clean untangling, some data remains with third parties. The GDPR offers concrete levers here, as the CNIL points out:
| Situation | Lever | With whom |
|---|---|---|
| Photos of you published by the other person | Right to object / withdrawal of consent | The platform, then the CNIL |
| Account closed but data retained | Right to erasure (art. 17) | The data controller |
| Itemised bill accessible to a third party | Contractual dispute | The operator, then the electronic communications ombudsman |
| Address still used for cold calling | Bloctel, targeted opt-out | The advertisers concerned |
Two realities to accept, however. First, erasure by a third party does not restore forgetting: whatever was copied locally has stayed there. Second, the delays are real — one month in principle, often longer in practice. The law is a long-term tool, not an emergency response.
Rebuilding cleanly: the new foundations
A separation is, paradoxically, the best opportunity to start again with sound digital hygiene. Three structural decisions are worth making now rather than in five years' time.
Separate your identifiers by use. One address for admin and banking, one for shopping and newsletters, one for social media. None of them serves as the recovery address for another, outside a carefully controlled pairing.
Choose a second factor that belongs to you. Neither the number of a plan you do not hold, nor a shared address. Backup codes, printed out and stored somewhere safe — a small combination safe is perfectly suited to documents and recovery keys.
Keep a discreet channel in reserve. For situations where a message needs to be sent without involving your number — making contact, passing information to a friend, taking a step you would rather not see appear on a bill — sending a message with a hidden sender from the web remains the simplest option. It requires no new SIM card, no registration and no installation. It is a compartmentalisation tool, not a means of concealment: it is to be used lawfully, without harassment or impersonation.
A one-page checklist
To be done within seven days of moving into separate homes:
- Main mailbox password changed, recovery addresses cleaned up
- Sessions and connected devices revoked on major accounts
- Automatic forwarding rules checked in every mailbox
- Two-factor authentication switched to a personal factor
- Mobile plan ownership clarified (or porting started)
- All location sharing switched off, trackers inventoried
- Family groups left, payment methods removed
- Router: administrator password and Wi-Fi key renewed
- Connected devices reset and re-paired
- Shared browser passwords purged, password manager set up
- Three months of bank statements reviewed for subscriptions
- Documents and evidence backed up offline
Conclusion: closing the doors one by one
Two lives that intersect leave behind a shared infrastructure, and that infrastructure does not dissolve on its own. It keeps running, with its access rights, its redirections and its histories, until someone decides to dismantle it methodically.
The work is neither long nor technical: a few hours, spread over a week, are enough to deal with the essentials. What is costly is getting started — because every box ticked brings you back to what you would rather put away. The reward is tangible: at the end of the list, nobody but you holds the keys to your digital life. That, in practice, is the definition of a fresh start.
