Photo by Benjamin Disinger on Unsplash
Landing a job is the easy part. Keeping it through the first year is where many people quietly fail. The hiring research firm Leadership IQ tracked more than 5,000 hiring managers and found that 46% of new hires were terminated, underperformed or quit within 18 months of starting. Only about 11% of those failures came down to a lack of technical skill. The rest were behavioural, relational, or about basic professionalism.
That gap between the offer letter and the 90-day review is where careers stall. This piece walks through 50 specific reasons people get let go after getting hired, with what actually goes wrong, what employers see, and what you can do differently. Some are obvious. A few will surprise you. None of them requires talent to avoid.
How the 50 reasons break down
The reasons cluster into a few broad areas: performance and skill, communication, attitude and fit, attendance and time use, integrity, conduct and policy breaches, adaptability, and the modern category of remote-work and digital-channel mistakes. You don’t have to fail at all of them to lose a job. One serious example, or three or four small repeated ones, is enough on most probation reviews. The good news: most are visible early and fixable if you catch them.
1. Lacking the skills the job actually needs
Interviews are imperfect. A hiring panel sees maybe four hours of you across calls, tests, and meetings, and then bets a six-figure cost on the call they made. When the gap between your CV and the day-to-day work shows up in week two, it shows up loudly. The fix isn’t faking ability you don’t have. It’s flagging the gap fast, asking for the training that closes it, and showing visible progress within 30 days. Most managers will fund the learning. Almost none will fund silence.
2. Refusing to learn new skills
Tools change. So do processes, clients, and team structure. A new hire who pushes back on every change (“we did it differently at my last job”) burns goodwill fast. According to SHRM, the average cost-per-hire in the US hovers around $4,700, and bad hires can cost three to five times that figure when you account for ramp-up, lost productivity, and replacement. Employers are looking for evidence that you’ll grow into the role over 2 years, not arrive fully formed and frozen.
3. Poor work ethic
A weak work ethic is rarely about hours. It’s the small signals: tasks half-finished, follow-ups dropped, deadlines treated as suggestions, and a default mood of inconvenience. Managers notice the pattern within weeks. If you’re new and unsure of the pace, ask. There’s a reasonable middle ground between burnout and visibly coasting, and most teams will tell you exactly where it is if you ask in your first 1:1.
4. A bad attitude that drags the team down
Skills are coachable. A persistently sour attitude is not, and it spreads. Gallup’s State of the Global Workplace research has consistently found that disengaged employees cost employers significantly more in lost productivity than the headline turnover numbers suggest. If you don’t want to be at the job, the people next to you will feel it within a fortnight. So will the people deciding whether you make it past probation.
5. Personality clashes you can’t smooth over
You won’t like everyone. You don’t have to. You do have to work civilly with the colleague who annoys you, the senior who micromanages, and the customer who’s rude on a Tuesday. If a relationship is actively souring, raise it once, calmly, with your manager. Letting it fester until it explodes in a meeting is what costs people their jobs. (A short read on managing your first 90 days helps here.)
6. Burning hours on personal social media
Phone-down policies exist for a reason. A 2024 ResumeBuilder survey of US workers found that the majority of office employees admit to spending well over an hour a day on personal social media during work. Most managers tolerate a normal amount. They notice when a new hire is on Instagram, WhatsApp, or TikTok every time they walk past your desk. In the first 90 days, especially, keep personal scrolling for breaks.
7. Inability to work on a team
Modern roles rarely sit alone. If you can’t share credit, give feedback that lands, take feedback without sulking, or pitch in when a colleague is buried, the team will route around you. And once a team routes around someone, that someone is on borrowed time. Most managers will give you one or two cycles to course-correct. After that, the conversation changes.
8. Misrepresenting your experience
Saying you’ve “led” something you observed, or claiming fluency in a tool you’ve opened twice, falls apart the moment a real task lands. Be specific in interviews about what you did versus what your team did. Honesty about the gap costs nothing. Discovery of the gap costs the job.
9. Missing deadlines and targets
A missed deadline isn’t fatal on its own. A missed deadline you didn’t flag in advance is. Managers can replan around a heads-up 72 hours out. They can’t replan around silence followed by an apology on the morning of. If something slips, say so as soon as you know, propose a new date, and protect the next deadline at all costs.
10. Poor verbal communication
Mumbling, talking over people, asking questions you’d have known the answer to if you’d listened, dominating meetings with monologues: these add up. Managers register them as “doesn’t communicate well” on probation forms, and that line is hard to argue with. Slow down. Take notes. Repeat what you heard back to the person who said it. Plain, calm, direct communication is the most underrated skill in any office.
11. Not asking about expectations
If your manager hasn’t told you exactly what success looks like by day 14, ask. (A short guide to asking for feedback in your first 90 days.) People get fired for missing targets they didn’t know existed. The fix is a single 30-minute conversation: what does good look like at 30, 60 and 90 days, in your manager’s own words.
12. Treating customers badly
You represent the company every time you talk to a client, a supplier, or a member of the public. One bad email screenshotted to the wrong person, one snippy phone call to a paying customer, and the calculus on whether to keep you shifts. The standard is consistent civility, even when the other person isn’t holding up their end.
13. Poor time management
Disorganised people miss things. Missed things cost money. Most modern roles assume basic time discipline: arriving prepared for meetings, knowing what’s due when, not losing 90 minutes a day to reactive busywork. If you’ve never had a system, build one in your first week. The system matters less than the fact that you have one.
14. Waiting to be told what to do
Seniors get fired for this faster than junior ones. The unwritten rule of most office work: figure out what needs doing and do it before someone asks. Junior hires get more rope, but the rope shortens fast after the first 60 days. Volunteer once a week for something visible that isn’t on your formal list. It changes how you’re seen.
15. Visibly checked out
If you don’t want the job, the room knows. There’s a difference between having a hard week and chronically signalling that you’d rather be anywhere else. Engagement is something you decide, mostly. If you genuinely can’t find a reason to care about the work, that’s a signal worth taking seriously before the company takes it for you.
16. Late in, early out without telling anyone
If you need to flex your hours, ask. Most employers will say yes to a reasonable request and no to a unilateral one. The act of asking is what shows you understand the relationship. Many modern offices run on core hours with flex around them. Confirm yours in week one and live inside them.
17. Posting about work on social media badly
The line is wider than it used to be, and people still trip over it. Venting about your manager on LinkedIn, leaking client names on Instagram stories, getting drawn into a public fight in the company’s mentions: any of these can end a job in 24 hours. Assume every post is screenshot-able and that someone you don’t want reading it will. Most employee handbooks now cover this explicitly, including grounds for summary dismissal.
18. Letting personal drama bleed into the office
Life happens. Bereavement, breakups, sick parents, custody battles. Reasonable managers expect this and accommodate it. What they don’t accommodate is months of being a daily emotional weather system at the team standup. If you’re going through something real, tell your manager once, agree on what support looks like, and protect the work where you can.
19. Lying on your resume
A 2023 ResumeBuilder survey found that around 70% of US workers admit to lying on their resume at some point: about job titles, dates, degrees, or skills. Most of those lies survive the interview. Fewer survive the first 60 days. The most common gotchas are dates that don’t match a background check, a degree that didn’t actually finish, and a former employer who quietly tells the truth on a reference call.
20. Disorganised and reactive every day
If your day is dictated by whatever lands in your inbox at 9 a.m., you’ll miss the things that matter. Reactive people look busy and ship little. Plan tomorrow at the end of today. Block time for the work that moves the needle. Defend that block from low-stakes meetings.
21. Failing to adapt when things change
Strategy shifts, your team gets reorged, your manager changes, and a major client churns. New hires who treat any of this as a personal affront get fired faster than people who roll with it. Adaptability is what employers test for in cases, references, and probation reviews. Show it.
22. Falling apart under pressure
Everyone has limits. Healthy workplaces respect them. But if a normal deadline regularly tips you into something that affects the work or the team, that’s a problem worth addressing before it’s the reason for your termination letter. If the pressure is itself unreasonable, raise it with your manager calmly and in writing. Stress and mental health are real concerns, and most employers in the US and UK now have specific obligations to accommodate them under disability and equality law.
23. Working on the wrong things
Busy is not the same as productive. New hires often confuse the two and end the quarter exhausted, with nothing to point to. Confirm priorities with your manager weekly. If you’re spending more than half your time on something that isn’t in your top three priorities, something’s wrong.
24. Refusing to accept feedback
This one is fatal in probation. Managers will give a new hire one piece of corrective feedback and watch what happens. If you push back defensively, deflect, or just don’t change anything, the manager has their answer. Take the note. Apply it. Mention it in your next 1:1 unprompted to show the loop closed.
25. Making excuses for mistakes
The strongest move after a mistake is a clean: “That was on me, here’s what happened, here’s the fix, here’s how I’m preventing the next one.” The weakest move is anything that starts with “to be fair.” Managers don’t expect new hires to be flawless. They do expect accountability.
26. Picking fights with colleagues
Disagreement is fine. Drawing your sword in a Slack thread or sniping at people in meetings is not. Argue the work, not the person. If you genuinely can’t get past a conflict, escalate it to your manager once, in private, with a concrete request. Then drop it.
27. Bullying others
Workplace bullying is a sackable offence in most companies, even at probation. The EEOC in the US and the equivalent equality bodies in the UK and EU treat patterns of bullying, especially when targeted at members of protected groups, as legal exposure for the employer. Don’t be the new hire who creates that exposure.
28. Breaking workplace rules
Read the handbook. Yes, all of it. The rules people get fired for breaching are usually the ones they assumed didn’t apply to them: expenses, gifts from suppliers, what you can take home from the supply cupboard, and who can sign what.
29. Skipping required training
Compliance training looks like box-ticking. It isn’t. If you skip the data protection module and then mishandle data three weeks later, the company has documented grounds for dismissal that won’t bend in your favour. Do the training when it’s assigned.
30. Showing up under the influence
Alcohol, weed, prescription misuse, anything that impairs judgment on the job. Safety-critical industries fire on the first occurrence. Office jobs usually warn first, then fire. If you have an addiction issue, most large employers in the US and UK now have employee assistance programmes that offer confidential support, and using them early is far better than being found out late.
31. Chronic absenteeism
Real illness, family emergencies, and protected leave (medical, parental, jury duty) are not what get people fired. Patterns of unexplained Friday and Monday absences do. So does failing to call in before the start of your shift. Know your sick-leave policy in week one and follow it precisely.
32. Chronic lateness
A few minutes late once a quarter is human. Twenty minutes late three times a week, with no flag and no apology, reads as disrespect. If your commute is genuinely the problem, ask about a flex schedule. If something else is the problem, fix it.
33. Refusing to be coached
A coachable hire is a 22-year-old who takes feedback from a 28-year-old and applies it on Monday. An uncoachable hire is a 45-year-old who explains why every piece of advice doesn’t apply to them. Seniority makes this worse, not better. Managers fire uncoachable hires faster than they fire weak ones, because at least the weak ones can learn.
34. Failing background or reference checks
A failed check after a job offer is usually the result of three things: dates that don’t match, a credential that didn’t finish, or a previous employer who tells the truth. Pre-emptively name the awkward thing on your CV. A six-month gap explained in an interview is fine. A six-month gap discovered in a check is a termination.
35. Taking credit for other people’s work
This breaks careers privately long before it breaks them publicly. Colleagues notice within weeks. By the time it reaches your manager, three people have already mentioned it independently, and the credibility damage is done. Credit generously. It’s the single highest-return habit in any office.
36. Failing a workplace drug test
Pre-employment and random drug tests are common in the US in safety-critical roles, transport, healthcare, and federal contracting. In the UK, they’re less universal but rising. A positive result is usually grounds for withdrawal of the offer or termination, depending on policy. Cannabis legality varies wildly by US state, but a state law allowing recreational use doesn’t override an employer’s drug policy in most cases.
37. Leaking information on Slack or Teams
Internal channels feel private. They aren’t. Anything you write is logged, discoverable in legal proceedings, and screenshot-able by anyone in the room. Forwarding a confidential deck to a personal email, gossiping about a colleague’s pay in a DM, or venting about a client in a “private” channel are all routine reasons people are walked out the door. Treat every message you send at work like it might one day be read by HR. Because it might.
38. Holding a second full-time job in secret
Remote work made “overemployment” easier and far more common. Most employment contracts require you to disclose any second paid role, and many prohibit a second full-time job outright. Getting caught (and people get caught, usually via overlapping meeting calendars or one of the two laptops dying mid-call) ends both jobs at once and burns the references.
39. Ignoring the dress code that actually exists
Dress codes today are a fraction of what they were a decade ago. Most offices run on a relaxed business casual or smart casual standard, and many tech and creative workplaces don’t enforce one at all. (A look at common dress code mistakes in modern offices covers the nuance.) Where dress codes do still exist (client-facing roles, regulated industries, court-adjacent work), they’re real and enforced. Find out what yours is in week one.
40. Refusing additional responsibility when offered
Saying yes to everything is a path to burnout. Saying no to everything is a path to being seen as un-promotable, and at probation, un-keepable. When your manager offers you a stretch, the default move is curiosity: what does the work involve, how does it fit your current load, and when is it due? Then a clear yes or a clear renegotiated yes.
41. Missing project deadlines after committing to them
Commitments are currency. Make one, and you spend the currency. Hit it, you earn more. Miss it without warning, and you go bankrupt. The fix is structural: don’t commit to a date you haven’t actually thought through, build slack into estimates, and surface risks early enough to be useful.
42. Visibly unproductive day after day
Some days you’ll be slow, and that’s fine. Some weeks, too. But if your manager can’t point to anything you’ve shipped in a fortnight, you’re in trouble whether they’ve said so or not. Keep a brief private log of what you finished each week. It helps your 1:1s, your performance review, and the day you have to defend yourself.
43. Never ask questions when you’re stuck
Spending two days stuck on something, a five-minute question could have unstuck it, is a rookie mistake. Senior managers expect new hires to ask. The skill is asking well: state what you’re trying to do, what you’ve already tried, and exactly where you’re stuck. (A short note on performance improvement plans versus termination.)
44. Misusing company equipment or accounts
Personal calls on a work mobile, personal errands in a company car, streaming services bought on the corporate card “by accident,” storing private files on the company laptop you’ll then return on your last day. All of these create paper trails. Most of them are firing offences if the company decides to make them ones.
45. Mishandling client data or compliance
In regulated sectors (finance, health, legal, government contracting), this is the fastest path from new hire to former hire. A mis-sent email containing client data, a screenshare with the wrong tab open, and a confidential file synced to a personal cloud account. Under GDPR in Europe and HIPAA in the US healthcare, the employer’s legal exposure starts the moment the breach happens. They will move quickly.
46. Publicly undermining your manager
Disagreeing with your manager in private is part of a healthy working relationship. Disagreeing with them in front of their boss, their peers, or your shared team is something else. People who do this on a probation review never make it to the next one. Take the argument behind a closed door.
47. Spreading gossip or trade secrets
The colleague who tells you something in confidence is testing you. Pass it on once, and they’ll know. The contract you signed almost certainly includes a confidentiality clause that covers commercial information, salaries, ongoing deals, and HR matters. Breaching it is grounds for dismissal in nearly every jurisdiction.
48. Inability to work independently
Most modern roles assume you can take a goal, scope the work, and ship it without daily hand-holding. If you need explicit instructions for every task at month three, the company is either over-managing you or you’re under-equipped for the role. Be honest with yourself about which.
49. Ghosting the job in your first weeks
A surprising number of new hires don’t make it through the first 30 days because they simply stop showing up. According to Bureau of Labour Statistics data, separations in the first months of tenure are among the highest in the job lifecycle. If a role isn’t working, resign properly. Walking out, or not turning up after a Monday lunch break, tanks your references and follows you longer than you think.
50. Crossing workplace conduct lines
Harassment, unwanted advances, repeated comments that single out colleagues for their gender, race, religion, sexuality or disability, retaliation against someone who raises a concern: every employer has a written policy on these, and most enforce them with summary dismissal. The burden isn’t only on junior staff. Senior employees and managers are held to a higher standard, not a lower one, and the legal landscape (US Title VII, the UK Equality Act 2010, equivalent EU directives) backs the employer’s right to act fast. If a colleague raises a concern about your conduct, take it seriously, apologise specifically, and change the behaviour. If you see something happening to someone else, report it. That’s what the policy is for.
Frequently asked questions
How long is a typical probationary period in the US and UK?
In the US, “probation” isn’t a legal term in private employment. Most employers run an informal 90-day review window, with at-will employment applying throughout. In the UK, contractual probationary periods of 3 to 6 months are standard, and dismissal during probation usually requires only a short notice period rather than full just-cause grounds. Always read your own contract for the specifics.
Can you be fired in the first week without warning?
In the US, under at-will employment, the answer is generally yes, with narrow exceptions for discrimination, retaliation, or protected leave. In the UK and most of the EU, employers can dismiss during a contractual probation with much lighter procedural requirements than after probation, though discrimination protections apply from day one.
What is the most common reason new hires get fired?
Research from Leadership IQ found that the leading causes of new hire failure are coachability, emotional intelligence, motivation, and temperament. Only about 11% of failures were attributed to technical skill gaps. The takeaway: most early-tenure firings are behavioural, and most are visible to a manager within 60 days.
How quickly should you raise concerns with your new manager?
Within the first 30 days for anything that affects your ability to do the job, and immediately for anything involving safety, harassment, or compliance. New managers expect early questions and read silence as either disengagement or hidden problems. A standing weekly 1:1 is the right venue for most of these conversations.
Does failing a drug test after hire always mean termination?
Not always. The outcome depends on the substance, the role’s safety requirements, the jurisdiction, and the employer’s written policy. Some companies offer a one-time chance with mandatory treatment, especially for prescription medication issues or for substances now legal in the state but still tested for. Safety-critical roles and federal contracting positions in the US tend to enforce strict zero-tolerance.
The honest conclusion
Most people who lose a job in their first year don’t do anything dramatic. They miss small commitments, dodge feedback, take a little too much credit, post one thing they shouldn’t have, and never quite ask what their manager actually wants from them. The patterns are visible. They’re also fixable. If you’ve just started a role, take the first 90 days seriously: ask the right questions, do the unglamorous work, log what you ship, and treat the manager relationship like the highest-leverage thing in your week. The people who survive their probation rarely look heroic. They just look reliable.
