By Paul Starbuck MCC, Founder and CEO of Starbuck & Associates
You would never let someone untrained sign off your accounts, handle your legal affairs or service your aircraft. Yet every week, in businesses across the UK, someone is handed responsibility for people, budgets and customers with no training in how to manage any of them.
The Chartered Management Institute and YouGov found that 82% of people entering management roles in the UK had no formal management or leadership training when they took up the role. The CMI calls them accidental managers.
Now think about what that means for your business. Every strategy you approve, every pound you invest and every promise you make to a customer reaches the front line through a manager. If four in five of them were never taught how to lead, your strategy is only as strong as the least prepared person delivering it.
The cost of staff turnover: the arithmetic most businesses never do
Let’s put some numbers on it.
Oxford Economics found that replacing a single UK employee costs a business £30,614 on average, most of it in output lost during the 28 weeks a new starter takes to reach full productivity. That figure is at 2014 prices, so today’s cost is higher. Lose five good people in a year and that is more than £150,000. You will not find it as a line in your accounts. It is hidden in recruitment fees, overtime, missed targets and clients who quietly drift away.
And the link to management is direct. Research by the CMI and YouGov found that half of UK workers who do not rate their manager plan to leave within a year.
Then there is productivity. Speaking in 2017, the Bank of England’s then chief economist, Andy Haldane, said that a one standard deviation improvement in the quality of management raises productivity by around 10% on average. Ask yourself what a 10% lift in productivity from the people you already employ would be worth. For most businesses, it dwarfs anything they will ever spend on developing their managers.
Why employees leave: the polite version and the real one
Your best people rarely tell you the truth on the way out. They mention a better offer, a shorter commute or more flexibility. You accept it, because it is easier for everyone.
The real reason is often much closer to home. The same CMI and YouGov research found that one in three UK workers has left a job because of a negative work culture. And the culture people experience day to day is set, more than anything, by the person they report to.
Your people are not leaving your business. They are leaving the experience of working in it, and that experience is shaped almost entirely by the manager they report to.
How accidental managers are made
It starts with a decision that looks entirely sensible. Your best salesperson is beating every target, so you promote them to run the team. Your sharpest engineer solves problems nobody else can, so they get the department.
In one move, you lose your top performer and gain a manager who has never been shown how to manage. Two losses for the price of one promotion.
The skills that made them excellent are not the skills they now need. Yesterday their value was what they delivered. Today it is what their team delivers. Many never make that shift. They keep doing the work themselves, step in whenever others struggle, and quietly become the bottleneck your growth runs into.
It is why we argue that coaching is a performance strategy, not a cost.
Five questions to bring to your next board meeting
- What did staff turnover cost us last year, in pounds rather than percentages?
- How many of our managers have had any formal training in leading people?
- When did a senior leader last ask our top performers whether they plan to stay?
- Are our senior people still doing the jobs they were promoted out of?
- If I stepped away for three months, would the business grow or stall?
If you cannot answer the first two with confidence, you are in good company. Most of the leaders we work with could not either, until they looked.
Developing new managers: what the best-run businesses do differently
The businesses that get this right treat management capability like any other asset. They invest in it deliberately, they measure it, and they do not leave it to chance. In our experience, three things make the difference.
First, they coach the people whose decisions shape everyone else’s day. Good executive coaching helps a new manager stop doing and start leading, and gives a senior leader an honest view of the blind spots their team is too polite to mention. If you are weighing up the options, we explain the difference between coaching and mentoring in a separate article.
Second, they look at the team, not just the individual. Some of the most expensive problems in a business are nobody’s fault. They sit in how a leadership team communicates, decides and trusts each other. Our team effectiveness programme pinpoints exactly where a team is getting stuck, then works with them to fix it. You can see all our team coaching and leadership team programmes on one page.
Third, they build managers before they need them. Leadership development for managers should come before the promotion, not years after it. Our Developing First Line Leaders programme gives new managers the confidence to lead teams, manage performance and develop people. And Starbuck Academy, our online learning platform, lets managers keep building those skills alongside the day job.
The businesses that win the next decade will not simply be the ones with the best strategy. They will be the ones whose managers can deliver it.
Book a free leadership conversation
If you have read this far, something has probably struck a nerve. A name, a team, or a resignation you never quite understood.
We offer a free leadership conversation to business owners, CEOs and directors, to look at what is really going on in your leadership team and where to start. Book your free leadership conversation, email hello@starbuckassociates.com or call +44 1529 240355.
About Starbuck & Associates
Starbuck & Associates is a B Corp certified coaching and leadership development company, working with organisations across the UK, Europe, the US, the UAE and Australia. We were named Coaching Business of the Year 2025 at the National Coaching Awards and are finalists for Learning and Development at The Investors in People Awards 2026 (see our awards). We also run ICF accredited coach training and publish Coachedâ„¢ magazine.
Frequently asked questions
What is an accidental manager?
Someone promoted into a management role, usually because they were good at their job, without any formal management or leadership training.
How much does it cost to replace an employee?
Oxford Economics found that replacing a UK employee costs £30,614 on average, mostly in output lost while a new starter reaches full productivity. That is at 2014 prices, so the cost today is likely to be higher.
How many UK managers have had no management training?
The Chartered Management Institute and YouGov found that 82% of people entering management roles in the UK had no formal management or leadership training when they took up the role.
Why do good employees leave?
Pay matters, but CMI and YouGov research found that one in three UK workers has left a job because of a negative work culture, and half of those who do not rate their manager plan to leave within a year. How people are led day to day is often the real reason.
How do you develop new managers?
Start before the promotion, not after it. Combine coaching for the individual, development for the team they lead, and ongoing learning they can fit around the day job.
