The one-person department: risks and hidden costs

Key takeaways

A one-person department is a function staffed by a single employee: the marketing person, the IT person, the finance person. It looks efficient and is fragile. There is no cover for about six weeks a year, nobody to check the work, and nobody inside the business able to judge whether it is good.

• About 6 weeks a year with nobody in the function: holiday plus average sickness.
• No peer review: errors and stale methods go unseen.
• No career path: capable people leave after 2 to 3 years.
• Back it up with documentation, a deputy and outside specialist depth.

What is a one-person department?

A one-person department is a business function carried out by one employee with no colleagues in the same discipline. It is common in businesses of 10 to 50 people, which need marketing, IT, HR and finance but cannot justify a team for each. The person is usually capable, busy and isolated.

• The hidden costs of doing everything in-house
• Key person dependency: when one person holds it all

What are the risks?

The risks are absence, quality and retention. A full-time employee has 28 days of statutory holiday, and the Office for National Statistics reports an average of 4.4 days of sickness absence per worker in 2024. That is around six working weeks a year in which the function stops or is covered by someone untrained.

• Absence: nothing happens when they are away.
• Quality: no second opinion and no challenge.
• Breadth: one person cannot be expert in every part of the function.
• Retention: no peers, no progression.
• Exit: the function's knowledge leaves in one resignation.

• Holiday and sickness cover for small teams
• The four eyes principle for small businesses

What does it cost?

It costs more than the salary. An employee on £35,000 costs about £40,363 a year under 2026/27 GOV.UK rates, before software, training and management. Add the work that waits during absence and the cost of replacing them when they leave, and a one-person function is rarely the cheap option it appears.

• The cost of staff turnover for UK small businesses

How do you back up a one-person function?

Back it up without hiring a second person by adding three things: written procedures, a trained deputy for the essentials and access to outside depth.

• Document the weekly and monthly routines.
• Train a colleague to run the essentials for two weeks.
• Hold credentials in a shared, secure store, not in one head.
• Use a specialist provider for overflow, cover and review.
• Give the person a peer network or mentor outside the business.

• The cost of undocumented processes
• Generalist vs specialist: who should do the work?

When does a one-person department work well?

It works when the person coordinates and specialists deliver. A marketing manager who sets direction and buys in design, video and ads has depth behind them. It works badly when one person is expected to do every specialism personally.

• When not to outsource

Which functions most often end up as a team of one?

Four functions account for most one-person departments in businesses of 10 to 50 people. Each is needed, none fills a team, and each covers several specialisms that no single person can hold.

• Marketing: strategy, content, design, ads and analytics in one role.
• IT: devices, accounts, security and suppliers.
• Finance: bookkeeping, payroll, credit control and reporting.
• HR: contracts, records, recruitment and employee relations.

• HR without an HR department: risks and costs
• Diseconomies of scale: when a bigger team costs more

What does the absence gap cost in practice?

The cost depends on what stops. If the finance person is away for two weeks and invoices are not raised, a business billing £60,000 a month delays about £30,000 of cash. If the marketing person is away, scheduled activity pauses and enquiries dip a few weeks later. If the IT person is away during an incident, everyone waits. In each case the salary continues while the output stops.

• Staff not taking annual leave: what it signals

How do you support the person in the role?

A sole specialist needs three things a team would normally provide: someone to check their work, someone to learn from and someone to share the load at peaks. An external reviewer or provider can supply the first and third. A professional network, a mentor or a small training budget supplies the second. Asking what they would hand over if they could is often the most useful question a manager can put.

What does this look like in practice?

A pattern we see with IT: one technically minded employee looks after everything from laptops to the phone system on top of their own job. They hold every admin password. Their two-week holiday is the riskiest fortnight of the year.

• See client work
• BPO Solutions for UK businesses

One-person department checklist

Check each single-person function.

• Who covers when they are away?
• Are the routines written down?
• Where are the passwords and logins held?
• Who reviews their work?
• What is their development plan?
• What specialist support can they call on?

• The hidden cost audit: score your business in an hour

Next step

Tell us which functions in your business rest on one person. We will suggest how to back each one up in a 30-minute call.