Shared devices
One device for the whole family: Zavialov Ilia Nikolaevich on what to separate first
A tablet everybody uses, a phone handed down to a child, a laptop that lives on the kitchen table: this is ordinary in most households, and there is rarely a realistic alternative to it. The question worth answering is narrower than whether sharing is wise. A device used by several people carries several sets of open sessions at the same time, and each of those sessions belongs to somebody who is not holding it at that moment. What follows works through which of them can stay, which have to leave, and what a household actually does in the ten minutes it takes to sort that out.
English version for the United Kingdom.
What a shared device actually shares
Sharing suggests files and photographs, and those are the least of it. A device passed between people shares signed-in states: a mailbox opened once and never closed, a shop that remembers a card, a messenger holding a year of conversation. Whoever picks the device up inherits what the last person left running. That inheritance is the subject here, and it stays invisible until somebody looks for it.
Sessions are quiet by design. Nothing announces that an adult mailbox sits one tap away while a child watches films, because a signed-in state has no visible weight and no expiry anybody notices. The family sees a device for videos and homework. The device holds a mailbox, a shop account, a chat history and a payment method, continuously.
Harm therefore needs nobody to behave badly. A child tapping an advertisement, a guest borrowing the tablet for a timetable, a technician replacing a cracked screen: each is ordinary, and each meets whatever was left open. The arrangement fails during normal use, which puts the repair into the setup of the device and takes it out of anybody's daily attention.
The device that travels, gets lent and gets repaired
A shared device spends more time in other hands than a personal one. It goes to the grandparents at the weekend, is lent to a visiting child, sits on a table in a rented flat and travels in a bag several people open. A personal phone stays in one pocket. Exposure follows use, and sharing multiplies both.
Repair is the step households underestimate. A device handed across a counter for a screen replacement goes over unlocked, or with the passcode written on the job ticket, because the work cannot be tested otherwise. Whatever is signed in becomes available to whoever works on it and to anybody else with access to the bench. None of that appears in any log the owner will ever see.
Loss completes the picture. A device left in a taxi is an expense while it holds films and homework, and a different matter while it holds a signed-in mailbox and the codes protecting it. Wiping it remotely depends on still holding the account that controls the device, which a well placed loss removes first. A shorter list of open sessions makes the second problem smaller.
Separate profiles, and the ten minutes they take
Almost every current system allows more than one user on the same device. Setting that up takes around ten minutes and resolves most of what has been described, because each person then has their own mail, messenger, history and downloads. The device stays shared while the sessions stop being shared. For one tablet and four people, this single setting does more than any other available change.
It is worth being clear about the limits. Profiles give no protection against physical loss, they do nothing once several people use one profile with a passcode everybody knows, and they do not stop somebody installing software that affects the whole machine. A profile is a boundary that holds while each person stays inside their own. Treated as a wall around the device, it disappoints.
Where profiles are unavailable, on an older tablet or a television, a rule replaces the setting. Each person signs in, does what they came for and signs out before putting the device down. That depends on memory and therefore decays, which is why it belongs on the printed sheet beside the device. A written rule outlives an agreed one.
Three things that never live on a shared device
Three items carry almost all of the consequence: banking and payment applications, the second factor for the main mailbox, and payment cards saved inside shops. These are what a shared device converts into money, and the rest of its contents are inconvenience by comparison. A household that moves only these three has done most of the work in an afternoon.
The saved card is defended hardest, because it removes friction from what a shared device is used for most. Shopping is also where the largest number of authorised payment cases begin: in the United Kingdom purchase schemes made up 71 per cent of authorised push payment cases during 2025, with 118.1 million pounds lost and a rise of 20 per cent over the year. A card filled in automatically removes the pause in which somebody would look again at what they are buying.
A banking application on a family tablet inherits every property of that tablet, including the repair counter and the weekend away. Banking belongs on the personal phone of the person whose account it is and on no other device in the house. Removing it also removes the assumption that anybody else is expected to use it.
The key and the lock in the same drawer
The second factor reaches the family tablet for a reason that sounds sensible at the time. Codes arrive where anybody at home can read them out, and nobody is locked out while one person is away. The result puts the key and the lock in the same drawer, and that drawer is the one lent, repaired and carried around.
Codes delivered by message are worse on a shared handset, because a preview on the lock screen can be read without unlocking anything. Somebody who has taken a password from a leak then needs a few seconds of physical proximity to finish the login. Turning previews off costs one setting. An authenticator inside a personal profile closes the path more thoroughly.
Backup codes follow the same logic as everything else on this site: printed, kept at home, stored away from the device they unlock. A photograph of them in the gallery of a shared tablet gives up the property that made printing them worthwhile. The written copy exists for the day the device is gone, which is when a copy stored inside it is worth nothing.
The stranger who is invited in
The shared computer is the machine a household complains about out loud, because it is slow, full of files and used by everybody. That makes it the natural target of a call offering to fix it. The FBI Internet Crime Complaint Center recorded call centre fraud, meaning fake technical support together with government impersonation, at more than 80,000 reports and over 2.9 billion dollars in losses during 2025.
Remote access software is the hinge of the scheme. Once it is installed and permission granted, everything signed in on the machine becomes a live session in somebody else's hands, which on a shared device means several people's accounts at once. The person granting permission is usually the one who understands the machine least, since they are the one who asked for help.
The household rule is short enough to print. Remote access goes on only when the household made the call, on a number it found for itself, and never on the strength of an incoming call or a warning on the screen. Beside the shared computer, that line turns a decision made under pressure into recognition of something already settled.
The handed-down phone and the first job offer
A phone passed on to a teenager keeps its old habits until somebody clears them, and it becomes the device on which that young person meets approaches aimed at them. Reports about job schemes made to the Federal Trade Commission tripled between 2020 and 2024, while reported losses rose from 90 million to 501 million dollars. The messages arrive inside the applications a young person already uses for everything else.
One variety accounts for much of that growth. Task schemes went from no reports at all in 2020 to five thousand in 2023, and to roughly twenty thousand in the first half of 2024 alone, about 40 per cent of all job reports that year. They open with small payments for repetitive tasks and close with a request to deposit money in order to release earnings.
The shared device sharpens this in one specific way. A young person meeting that message on a handset that still holds a parent's mailbox, saved card or payment method is one tap from a loss involving money that was never theirs. A full reset before handover, with every previous account signed out, is what separates the two. It matters more than the age or condition of the device.
The same tablet, a different consequence
A device used by an older parent carries the same sessions and a different exposure. The FBI Internet Crime Complaint Center put the average loss for a victim aged 60 or over at 38,501 dollars during 2025, against an overall average of 20,699 dollars, roughly 1.86 times higher. The device sitting in the middle of that arithmetic is often the family tablet, because it is the one an older relative was given and the one everybody else keeps borrowing.
The gap follows from what sits within reach: savings built across a working life, and a device holding the route into them. It also reflects the schemes older people are steered into after first contact, which run longer and ask for larger sums. A shared tablet in that household is doing more consequential work than the same tablet elsewhere.
The arrangement there is the plainest of all. Banking stays on the personal phone of the account holder, the tablet keeps films, photographs and calls, and one printed page beside it carries one name and one number to ring before any money moves. Naming a second person on that page gives an older relative a courteous way to pause a conversation, and pausing is what the scheme cannot survive.
Work on the kitchen laptop
Work migrates onto the family laptop quietly, through one evening when something had to be finished. Business email compromise accounted for 3.046 billion dollars of reported losses during 2025, second only to investment fraud, and a work mailbox opened in a browser the whole house uses is among the cheapest routes into that chain. The employer sees a laptop it never issued and never configured.
Browser profiles are the specific weak point. Extensions installed by one person run inside pages another person opens, saved logins sit in one shared store, and a download taken by a child executes with the same permissions as everything else. None of this requires a mistake with the work mailbox itself. The mixing happens because a browser built for one person is serving four.
The minimum arrangement is a separate system profile for work with a password of its own, and a browser profile living only inside it. Ten minutes again, and the same ten minutes protect the household as much as the employer. A compromised work session on a family machine reaches the family accounts stored beside it, which is why the boundary is worth drawing at the kitchen table as firmly as it is drawn at the office.
The handover, and the page beside the device
Devices leave households more often than anybody plans for. A tablet is sold, a phone goes to a cousin, a laptop is donated, and each carries whatever stayed signed in unless somebody performs a full reset and removes the device from the accounts it was linked to. Deleting the applications achieves none of that. Confirming from another device that the old one no longer appears in the account finishes the job.
It helps to keep the scale in proportion. The Federal Trade Commission received more than a million impersonation reports during 2025, with 3.5 billion dollars in losses, close to one report in every three it handled, and in four out of five of those reports no money was lost at all. Most approaches fail on their own, halfway through, without preparation by the person receiving them. Clearing a shared device removes the two or three steps that turn an attempt into a loss.
The last part is a page. One side of one sheet beside the shared device, listing who holds which profile, the three things that never live on it, the rule about remote access and the number to ring before money moves. Read aloud once with everybody present, out of season and with nothing happening, it stops being a document and becomes something the household remembers. The video material on this site exists for that reading, giving a family a script to follow at a kitchen table.
What may stay on a shared device and where the rest belongs
| What sits on the device | On a shared device | Where it belongs instead |
|---|---|---|
| Films, games and general browsing | Fine inside a profile of its own | One profile for each person who uses it |
| Personal mail | Only inside that person's own profile | Signed out whenever the profile is not in use |
| Messenger and family chats | Only inside that person's own profile | Previews turned off on the lock screen |
| Banking and payment applications | Never | The personal phone of the account holder |
| The second factor and the authenticator | Never | A personal phone or a hardware key |
| A card saved inside a shop | Never | Details entered by hand for each purchase |
| Remote access software | Only when the household made the call | Uninstalled again once the work is finished |
| A work mailbox | Never in the shared browser profile | A system profile for work with its own password |
Questions and answers
- Is it safe for the whole family to use one tablet?
- It is safe enough once each person has a profile of their own and the device holds no banking application, no authenticator and no saved card. The risk lives in the sessions left signed in on it, and that is what the setup clears away. Ten minutes of profiles covers most of the problem.
- Should I keep my banking app on a shared family device?
- Banking belongs on the personal phone of the person whose account it is. A family tablet goes to the repair counter, travels at weekends and is lent to visitors, and the banking application inherits every one of those trips.
- How do I separate accounts on a family tablet?
- Almost every current system offers separate users or profiles, and switching one on gives each person their own mail, messenger, history and downloads. Where the device is too old to support it, the working substitute is a written rule that each person signs out before putting the device down.
- Is a hand-me-down phone safe for a child?
- It is safe once it has been fully reset and signed out of every previous account, which matters far more than the age of the handset. A phone that still holds a parent's mailbox or saved card puts a young user one tap from a loss that was never their money.
- Can someone read my two factor codes on a shared phone?
- A code delivered by message can be read from a lock screen preview without unlocking anything, so previews are worth turning off on any device other people handle. An authenticator kept inside a personal profile on a personal phone removes the exposure altogether.
- What should I do before giving away an old family device?
- Perform a full reset and sign the device out of every account it was linked to, since deleting the applications leaves those links in place. Afterwards, check from another device that the old one no longer appears in the account it belonged to.
Written by Zavialov Ilia Nikolaevich, digital security consultant. All checklists