The real cost of a bad hire in engineering

A mid-level engineering hire that does not work out typically costs between £30,000 and £50,000 by the time you account for everything. Most businesses only count the recruitment fee. The rest of the costs are real, they just do not appear on a single invoice.

Here is how to calculate your actual exposure and, more usefully, how to reduce it.

What are the direct costs?

Direct costs of a failed mid-level engineering hire total £33,000 to £38,000, covering the original agency fee of roughly £9,000 on a £50,000 placement, £15,000 to £16,000 in fully loaded salary for three months of underperformance, and a further £9,000 to £12,000 for the replacement process. That figure is before any project or morale damage.

Start with the recruitment fee. A specialist agency placing a £50,000 mechanical engineer at 18% of salary costs you £9,000. That fee is gone if the placement fails after the guarantee period, or after a shortened tenure that technically clears the guarantee but still results in a departure.

Add the salary paid during the period the person was not performing. If an engineer is underperforming for three months before the situation becomes unmanageable, that is £12,500 in salary alone. With employer National Insurance, pension contributions, and any benefits, the true cost is closer to £15,000 to £16,000.

Add the cost of the replacement process: another recruitment fee, management time in briefing and interviewing, and any advertising costs if you run a direct process first. You are back to £9,000 to £12,000 minimum.

Total direct costs: £33,000 to £38,000 for one failed mid-level hire. And that is before anything more complex happens.

What are the hidden costs?

Hidden costs of a bad engineering hire typically add £10,000 to £20,000 on top of the direct figure, pushing total exposure past £50,000. Those include project delays and schedule slippage, team morale and productivity drag, 30 to 50 hours of senior management time at a fully loaded £60 to £80 per hour, and potential client relationship damage in customer-facing roles.

Project delays are the hardest to quantify but often the most significant. A mechanical design engineer who leaves twelve weeks into a product development programme has cost you schedule. Depending on the project, that schedule impact might mean a delayed launch, a missed contractual milestone, or a client conversation you did not want to have.

Team morale and productivity take a hit. The engineers around a poor hire spend time compensating, covering gaps, or managing the friction. That cost is invisible on a spreadsheet but very visible to the people experiencing it.

Management time is significant. Handling performance concerns, holding difficult conversations, working through HR processes, and then re-briefing a replacement hire might consume 30 to 50 hours of a senior manager’s time over three to four months. At a fully loaded cost of £60 to £80 per hour for a senior engineer or technical manager, that is £1,800 to £4,000 in management hours.

If the role is client-facing, there is potential relationship damage. A project manager or sales engineer who performs poorly in front of a client leaves an impression that takes time to correct.

Combined, these hidden costs can add £10,000 to £20,000 to the direct figure above, pushing the total well past £50,000 for a single failed hire at this level.

How do you reduce the risk?

The most effective interventions to reduce bad-hire risk happen before the offer: technical screening conducted by a peer engineer rather than HR, job descriptions that self-select correctly on on-site and flexibility expectations, and structured 30, 60, and 90-day check-ins during probation. YP Recruitment placement guarantee periods typically run eight to twelve weeks, but reducing probability through proper briefing matters more than the refund.

The most effective interventions happen before the offer, not after.

Technical screening matters. A competency-based interview is not sufficient for most engineering roles. If you are hiring a stress analyst, have a stress analyst on the interview panel. If you are hiring a process engineer, ask them to walk through a real process problem. Generic interviews run by HR or a generalist hiring manager miss technical red flags that a peer would spot immediately.

Job descriptions that self-select correctly. If the role requires five days on-site and involves repetitive process work, say that clearly. A candidate who reads that and applies is making an informed choice. One who joins expecting hybrid working and variety, and finds neither, is a higher flight risk from week one.

Structured onboarding with 30, 60, and 90-day check-ins. Most engineering businesses treat probation as a formality. The 90-day review happens, a box is ticked, and nobody has a real conversation about how the hire is settling in until something goes wrong at month seven. Structured check-ins catch misalignment early, when it is still fixable.

Honest job descriptions also reduce early departures. If the progression opportunity you described at interview does not materialise in twelve months, the engineer starts looking. Promises that are not backed by a plan are a retention liability.

A note on guarantee periods

Good recruitment partners offer a guarantee period, typically eight to twelve weeks, during which a replacement or partial refund is provided if the placement does not work out. That mitigates a portion of the direct cost, but it does not address the hidden costs described above.

The more valuable thing a specialist recruiter does is reduce the probability of a bad hire in the first place, by screening properly, briefing candidates honestly, and only presenting people who are genuinely qualified and genuinely interested.

Read more about our placement guarantee or explore our engineering recruitment approach if you want to understand how we work to reduce this risk for our clients.