The cost of an unfilled vacancy

Key takeaways

The cost of an unfilled position is the output lost, the overtime paid and the backlog built while a role is empty. For a £28,000 admin role, covering 30 hours a week in overtime costs about £750 a week, and lost enquiries often cost far more. A six to eight-week vacancy often costs more than the recruitment itself.

• £750 a week buys 30 hours of overtime cover for a £28,000 admin role.
• Overtime at time and a half costs about £25 an hour for a £28,000 colleague.
• Backlog and slower replies cost sales that never show in the accounts.
• A managed team can often start in about two weeks.

What does an unfilled vacancy cost?

An unfilled vacancy costs whatever the role would have produced, minus the pay you are not spending, plus the cost of covering it. In customer-facing roles, the largest part is often lost sales from slower responses. In back-office roles, it is overtime and backlog that must be cleared later.

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How do you calculate vacancy cost?

Estimate these weekly and multiply by the weeks the role is empty.

• Overtime or temp cost to cover part of the work.
• Output or revenue lost for work not covered.
• Backlog that must be cleared later.
• Manager time spent covering.
• Minus: the salary you are not paying.

What does a worked example look like?

A £28,000 administrator leaves and the role is empty for 8 weeks. A colleague covers 30 hours a week in overtime at time and a half, about £25 an hour including employer costs, which is £750 a week. The saved salary is about £615 a week, so the net cost looks small, but the owner covers the rest, and replies slow down.

If slower replies lose two enquiries a month worth £1,500 in margin each, the vacancy costs about £6,000 in lost margin over 8 weeks, far more than the overtime.

• Slow response to enquiries: what it costs and the fix

What are the rules on overtime and working hours?

Adults cannot be made to work more than 48 hours a week on average unless they opt out in writing, and overtime pay depends on the contract. Average pay must not fall below the National Minimum Wage. Covering a vacancy with long hours for weeks also raises burnout and the risk of a second leaver.

• Small team burning out? Capacity is the fix

How can you cover a vacancy faster?

Options include temps, a part-time contractor, redistributing work, or an outsourced team. Temps suit on-site work; outsourcing suits remote, repeatable tasks and can often start within about two weeks. Some businesses then keep the outsourced team rather than re-hiring.

• Outsourcing vs temp agency staff
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Why do vacancies last longer than planned?

Advertising, screening, interviews and the candidate's notice period add up, and a failed first round restarts the clock. The ONS jobs and vacancies bulletin tracks how tight the labour market is; when vacancies are high, filling roles usually takes longer.

• What it costs to recruit an employee in the UK

Which roles cost the most to leave empty?

Customer-facing and revenue-linked roles cost the most, because lost enquiries and slower replies turn directly into lost sales. Back-office roles cost more slowly, through backlog and overtime, until invoices go out late or errors build up. Prioritise cover for the roles where delay loses customers.

• Highest cost: reception, enquiry handling, sales support.
• Medium cost: customer service, order processing, invoicing.
• Lower short-term cost: filing, reporting, internal admin.

• Losing leads to slow follow-up? When to outsource it

What does this look like in practice?

A pattern we see in UK logistics firms: the customer service coordinator hands in notice during a busy quarter. Tracking queries pile up and account managers answer them instead of selling. A managed team takes the queries within a couple of weeks, and the business decides later whether to re-hire.

• See client work

Vacancy cost checklist

Use these steps as soon as someone resigns.

• Estimate weeks until a replacement is fully productive.
• Cost overtime and manager cover per week.
• Estimate lost enquiries, sales or bookings.
• Compare with temp and outsourced cover.
• Decide within a week, not after the backlog builds.

Next step

Tell us which role is empty and what it covers. We will cost the vacancy and a managed cover option in a 30-minute call.