Introduction: the listing that says too much
You're selling an old bike. You take three photos in the garage, you write "good condition, barely used", you note "collection in person, station area", and you leave your first name and mobile number "to speed things up". Posted in four minutes, the listing is viewed three thousand times in two days.
What you have actually just broadcast publicly: the make of your car visible in the background, the living-room French window complete with its lock model, your neighbourhood down to the block, a window of availability that gives away the hours you're out, and a phone number which, searched as-is in a search engine, brings up your 2023 rental ad and your profile on a running forum. The bike is a minor detail.
Peer-to-peer resale is one of the few everyday activities in which we publish, voluntarily and by our own hand, a fairly complete file on ourselves. According to the Autorité de la concurrence and sector reports on the secondhand market, several tens of millions of French people use at least one resale platform. Almost none of them has stopped to consider what their listing says about them. This guide fixes that, step by step, without giving up on selling.
What a listing really reveals
The metadata in your photos
Every photo taken with a smartphone carries EXIF data: device model, precise date and time, settings, and very often the GPS coordinates of where the shot was taken. Major platforms generally strip these fields at upload — but not the messaging apps you use to send "one more photo" to an interested buyer, nor email attachments, nor more homespun classified-ad services.
The reflex to build: check and delete metadata before any transmission outside the platform. On both iOS and Android, the option exists natively in the share sheet ("Options" → turn off "Location data"). On a computer, a right click → Properties → "Remove Properties and Personal Information" under Windows does the job.
The background, that informant
Visual content weighs far more heavily than EXIF. A photo of your home interior documents:
- the layout of your windows, shutters and locking systems;
- the apparent level of your equipment (television, hi-fi, instruments, bikes);
- letters, street signs, badges, prescriptions or labels legible in the background;
- the presence or absence of children, pets, or an alarm system.
The countermeasure is simple and costs a few seconds: photograph the item on its own, against a neutral background. A simple foldable fabric photo backdrop or a plain tablecloth spread over a table is enough to make all context disappear, while markedly improving the perceived quality of the listing — and therefore the sale price. The benefit is twofold, which is rare where privacy is concerned.
The text
"Selling because I'm moving to Lyon at the end of October." You've just announced a date on which your home will be empty. "Available after 6pm on weekdays" reveals your schedule. "A gift from my ex" gives away a personal situation. Write like a shopkeeper: the item, its condition, its price. Nothing else.
Your phone number: the main leak
Why it's the weak link
A mobile number is now an almost unique and lasting identifier. It serves as a matching key between databases, an entry point for cold-calling, and a lever for tech-support fraud or account takeover attempts. Once published in a listing, it is hoovered up within hours by harvesting bots and resold in marketing files.
The CNIL regularly points out that collecting and reusing contact details for marketing purposes without consent is unlawful — but the penalty comes after the harm, never before.
Levels of protection
| Method | Convenience | Protection | Limitation |
|---|---|---|---|
| Platform's internal messaging | High | Good | Depends on the platform, history retained |
| Masked/relay number offered by the site | High | Good | Not available everywhere |
| Dedicated second prepaid SIM | Medium | Very good | Cost, managing a second number |
| Secondary number via an app | High | Variable | Uneven quality among providers |
| Sending an SMS without revealing your number | High | Excellent for outgoing messages | Cannot receive replies on this channel |
In practice, the most robust combination is to stay on the platform's messaging right up to the last moment, then, if direct contact becomes necessary (confirming a meeting, running late, changing location), to use a channel that doesn't disclose your personal line. An anonymous SMS service is perfectly suited to this kind of one-off, one-way message: "Hello, I'll be outside the bakery at 6.15pm, blue jacket." The information gets through, your number stays with you.
For those who sell regularly, the lasting solution remains a dedicated line: a no-commitment prepaid SIM kept in an old handset, or slipped into a dual-SIM mobile phone used day to day. The number serves for listings, deliveries and commercial sign-ups — and nothing else. The day it leaks, you bin it.
Meeting in person: anonymity and safety go together
Never have people come to your home (by default)
This is the rule most sellers break out of convenience. Inviting a stranger to your home means giving them the address, showing them the interior, and revealing who lives there. Police and gendarmerie services regularly report reconnaissance carried out under the cover of a secondhand purchase.
The alternatives, in order of preference:
- A busy, covered public place: a station concourse, a shopping centre, a town-hall forecourt.
- A supermarket car park, during the day, in a CCTV-monitored area.
- A police station or gendarmerie: many stations unofficially allow transactions to take place on their forecourt, and some advertise it explicitly.
- A parcel pickup point, when the item is small and shipping is an option.
If the item is bulky and a visit to your home is unavoidable (furniture, white goods), tell someone close to you the time, don't let the buyer wander about, put away any visible documents, and never leave the person alone in a room.
Paying in person
Cash remains the most discreet payment: no name, no IBAN, no transaction trail. It is perfectly legal between private individuals up to €1,000 for a French tax resident (Article L.112-6 of the Monetary and Financial Code). Above that, a traceable method is mandatory.
Two precautions:
- Check the notes. Counterfeit bills circulate particularly on secondhand transactions in the €200 to €600 range. A counterfeit banknote detector pen costs a few euros and slips into a pocket; the Banque de France above all recommends checking the raised print and watermark by touch.
- Refuse transfers "already sent, you'll see it tomorrow". An instant transfer can be verified in your banking app in ten seconds. A standard transfer doesn't exist until it has been credited.
Peer-to-peer payment apps, by contrast, expose your name, sometimes your photo and your number. That's not trivial: a buyer who obtains your full name and your neighbourhood already has the essentials.
The scams that exploit your desire for discretion
Secondhand sales fraud is among the best documented by the official platform Cybermalveillance.gouv.fr and by the Perceval bank card fraud reporting scheme. Three patterns dominate.
The fake delivery link
The buyer insists on moving off the platform and sends you a "shipment validation" link imitating a payment service or a courier. The page asks for your card number "in order to receive the funds". No payment collection ever requires a card number: receiving money only requires an IBAN, never a security code.
The overpayment
The fraudster claims to have transferred €900 instead of €400 and asks for an immediate refund of the difference. The initial transfer is fictitious, later disputed, or made from a hacked account. Absolute rule: never refund anything before the payment has definitively cleared and appears on your statement.
Identity theft, piece by piece
More insidious: the buyer asks for a copy of the purchase invoice, then an ID document "for the warranty", then a proof of address "for the registration document". Each request seems innocuous. The file thus assembled can then be used to take out a consumer loan. For the sale of a bike or a games console, none of these documents is necessary. Only the sale of a motor vehicle imposes identity formalities (Cerfa 15776 transfer certificate), and in that case you send an ID document struck through with a handwritten note stating its purpose and the date.
What the tax authorities and the platforms actually know about you
There's a stubborn confusion between discretion and illegality. Let's set the record straight.
Since 2024, the European DAC7 directive has required platforms to report annually to the tax administration the identity, address, tax number and amounts received by sellers exceeding 30 transactions or €2,000 in sales over the year. Below those thresholds, no reporting takes place.
On the substance of tax law, the doctrine of the Direction générale des Finances publiques is settled: the resale of personal secondhand items is not taxable, with two exceptions — precious metals, and goods sold for more than €5,000 (excluding household furnishings, appliances and cars). Selling your sofa, your phone or your clothes triggers nothing.
The practical consequence is important: wanting to remain discreet in a secondhand sale is neither suspicious nor fraudulent. It's simply refusing to compile, free of charge, a commercial file on yourself.
That doesn't exempt you from a regular clear-out. The GDPR gives you a right of access (Article 15) and a right to erasure (Article 17) on any platform. A resale account left dormant for three years still holds your old listings, your conversations, your history of delivery addresses and sometimes the ID document you uploaded during a verification. Request the export, then the deletion.
Postal shipping: the other address leak
When handing the item over in person isn't possible, shipping raises a mirror-image problem: the parcel carries your return address.
A few realistic options:
- Drop off at a pickup point with the pickup point as sender: several couriers let you list the pickup point as the return address.
- Use a consistent name for practical purposes: your first name and surname are needed for delivery, but the address can be that of a drop-off point or a post office with a mail-holding service.
- Don't slip anything identifying into the parcel: the original invoice, a dry-cleaning tag, or a prescription used as padding are classic leaks. A roll of plain bubble wrap and a few basic padded envelopes save you from improvising with whatever is lying around.
For valuable items, discreet labelling matters too: a plain cardboard box attracts less attention than original packaging announcing a high-end laptop. Thefts in transit target first and foremost whatever advertises itself.
Erasing the traces inside the item
This is the forgotten dimension. A secondhand item often carries data with it.
- Phone, tablet, computer: factory reset, sign out of the manufacturer's account beforehand (otherwise the device stays locked and the buyer will come back to you), remove the SIM and memory card.
- Games console: delete the account, deregister the console as "primary".
- Car: erase synced contacts, home/work addresses in the sat-nav, and paired phones.
- Connected devices (watch, speaker, robot vacuum that maps your home): reset and remove the device from the associated account.
- Hard drives and USB sticks: simply deleting files isn't enough. Wiping by overwriting, or physically destroying the media, is the only guarantee. For individuals sorting through a lot of old media, a hard drive adapter enclosure lets you plug in, wipe properly and verify before reselling.
Conversely, when you buy secondhand, always reset the device yourself on receipt: a resold smartphone or router may retain a remote management account, a tracking app installed by the previous owner, or a configuration profile.
The discreet transaction checklist
Five minutes of preparation beats six months of cold-calling and an address out in the wild.
Before posting
- Photos of the item alone, neutral background, metadata stripped.
- Factual text: no moving date, no schedule, no personal context.
- A neutral username, unconnected to your other accounts.
- No phone number in the body of the listing.
During the exchange
- Internal messaging only; a reasoned refusal of any move off-platform.
- No identity documents sent, except where legally required (vehicles).
- No banking details other than an IBAN, never a card number.
At the point of transaction
- Public place, in daylight, with someone close informed.
- Cash checked, or transfer confirmed as credited.
- Item reset, no documents left inside.
Afterwards
- Delete the listing and the conversations.
- Purge the account after a few months of inactivity (right to erasure).
- Keep the dedicated number for future sales, or replace it if it starts attracting cold calls.
Conclusion: selling without selling yourself
The secondhand economy is good news, ecologically and financially. It is also, quietly, one of the largest voluntary personal data collection programmes ever set up: millions of people documenting their home, their equipment, their schedules and their circumstances every week, in exchange for a few tens of euros.
None of this is inevitable. No platform requires you to show your living room, no buyer needs your full name for a microwave oven, no law obliges you to leave your personal number in plain sight on a public page. Discretion, here, isn't paranoia: it's the digital version of the instinct not to post the contents of your flat on the front door of your building.
Sell the bike. Keep the rest.
