5 Mistakes Every New Manager Makes (And How to Avoid Them)

Getting promoted into your first management role is one of those moments that feels great for about forty-eight hours.

Then the reality sets in.

Suddenly, your success isn’t measured by what you produce – it’s measured by what your team produces.

The skills that got you promoted aren’t necessarily the skills that will make you effective in this new role.

And nobody hands you a manual for making that shift.

The good news?

Most of the mistakes new managers make are entirely predictable.

I’ve seen them again and again in the leadership and management training I deliver to organisations across the UK.

Smart, capable people making the same handful of missteps because nobody warned them in advance.

So here are five of the most common mistakes new managers make, why they happen, and – more importantly – what you can do instead.

New Managers make mistakes - here are five of the biggest ones to avoid

1. Trying to Do Everything Yourself

This is probably the single most common trap new managers fall into, and it makes complete sense when you think about it.

You got promoted because you were excellent at doing the work. You know how to do it well.

You know how to do it quickly.

So when a task lands on the team’s plate, your instinct is to just crack on and do it yourself.

The problem is that this doesn’t scale.

You can’t do your old job and your new job at the same time – at least, not for long.

And every task you hold onto is a task your team doesn’t get the chance to develop through.

The real shift here is understanding that your job is no longer to do the work – it’s to make sure the work gets done. 

That’s a fundamentally different thing.

It means delegating tasks you could do perfectly well yourself, accepting that someone else might do them slightly differently, and investing time in coaching and supporting rather than executing.

Pick one or two tasks you’re currently holding onto and hand them over properly – with clear expectations, the right support, and a check-in point so you’re not just throwing someone in at the deep end.

Learning how to prioritise and manage your time is also key for new managers.

You’ll be amazed how much headspace it frees up.

2. Avoiding Difficult Conversations

Nobody enjoys difficult conversations.

But for new managers, there’s an extra layer of discomfort: you might be managing people who were your peers last week.

You want to be liked. You don’t want to rock the boat.

So when someone’s performance isn’t up to scratch, or there’s tension in the team, the temptation is to hope it sorts itself out.

It almost never sorts itself out.

What actually happens is the issue grows.

Other team members notice.

They start wondering why you’re not dealing with it.

Your credibility takes a hit – not because you had the conversation badly, but because you didn’t have it at all.

The key thing to understand is that having a difficult conversation early, when the issue is small, is almost always easier than having it later when it’s become a pattern.

You don’t need to be aggressive or confrontational. You just need to be honest, specific, and timely.

A simple approach:

1. Situation (when/where)

2. Behaviour (observable facts)

3. Impact (on performance / customer / team / quality / time / safety etc)

4. Feedforward = what to do next time, by what standard, and what support you’ll provide.

“When [situation], I observed [behaviour]. The impact was [impact]. Next time, please [specific behaviour / standard]. I’m saying this because your success matters to me and I trust you can do it. What can I do that would help you?”

That’s it.

No drama, no ambush – just a straightforward conversation between two adults.

Bonus tip: Ask for their perspective (“what’s going on from your side?”).

You won't have all of the answers and might only have one side of the story.

Having the conversation now is always better than waiting and hoping the issue will disappear

3. Thinking You Need to Have All the Answers

There’s an unspoken assumption many new managers carry: that being in charge means being the person who knows everything.

So when someone asks a question you don’t know the answer to, it feels like a failure.

You might bluff your way through, or spend hours researching something you could have just asked someone else about.

Here’s the thing – your team doesn’t need you to know everything.

They need you to help them find the answers, remove obstacles, and make decisions when things are ambiguous.

That’s a completely different skill set.

Some of the most effective managers I’ve worked with are perfectly comfortable saying “I don’t know, but let me find out” or “What do you think we should do?”

That’s not weakness – it’s confidence.

It shows your team that you trust their expertise and that you’re secure enough to not pretend you have all the answers.

This also has a practical benefit: it develops your team. If you always provide the answer, people stop thinking for themselves.

If you coach them towards the answer, they grow – and you build a team that’s more capable and less dependent on you.

Related training If this topic is relevant for you or your team, these courses may also help: Leadership & Management Skills Time Management Training Communication Skills Training

AI and Microsoft Office Training

4. Not Making the Shift from ‘Doer’ to ‘Enabler’

This is closely related to mistake number one, but it goes deeper.

It’s not just about delegating tasks – it’s about fundamentally rethinking how you measure your own success.

As an individual contributor, you probably measured a good day by what you got done.

How many things did you tick off? How much did you produce?

That’s a satisfying way to work, and it’s hard to let go of.

But as a manager, a good day might look completely different.

It might be a day where you had a coaching conversation that helped someone crack a problem they’d been stuck on.

Or a day where you cleared a bureaucratic blocker so your team could get on with their work.

Or a day where you sat in a planning meeting and made sure your team’s priorities were protected.

None of those things feel as immediately satisfying as ticking off a task, but they’re the things that actually make a team work well.

Try this: at the end of each week, instead of asking yourself “what did I get done?”, ask “what did I enable my team to get done?” 

It’s a small reframe, but it can genuinely change how you approach each day.

5. Neglecting Relationships Upward and Sideways

When you become a manager, it’s natural to focus all your attention downward – on your team.

They’re the people you’re now responsible for, and getting those relationships right feels like the priority.

But here’s what often gets missed: you also need to manage upward and sideways.

Your relationship with your own manager matters enormously.

They’re the person who can give you resources, shield you from unnecessary noise, support your decisions, and advocate for your team.

If you’re not keeping them informed and aligned, you’re making your job harder than it needs to be.

The same goes for your peers – other managers at your level.

These are the people you’ll need to collaborate with, negotiate resources with, and occasionally disagree with.

Building those relationships early, before you need something from them, makes everything smoother down the line.

This doesn’t need to be political or strategic in a cynical way.

It’s simply about making sure you’re not operating in a bubble. Keep your manager updated. Ask them what they need from you.

Have coffee with your peers. Understand their priorities. It’s all part of the job – and it’s a part that many new managers only discover when things go wrong.

The Common Thread in New Manager Mistakes

If you look at all five of these mistakes, there’s a pattern running through them.

They’re all, in some way, about struggling to let go of what made you successful before and embracing a completely different way of adding value.

That’s the real challenge of becoming a manager.

It’s not about learning a set of techniques – although the right techniques absolutely help. It’s about making a fundamental shift in how you see your role.

You’re no longer the person who does the work.

You’re the person who makes sure the right work gets done, by the right people, to the right standard.

And if you can get comfortable with that shift, you’ll avoid most of the pitfalls that trip new managers up.

If you’re a new manager – or about to become one – and you’d like some structured support in making that transition, take a look at my leadership and management courses.

I can also run in-house training for your team if you have a group of managers you are looking to upskill.

They’re designed to give you practical tools and real confidence, not just theory.

Contact me to learn more.