You have someone in your team who has been strong for years. They know your clients, know how your firm works, and their colleagues trust them. A role comes up, either through growth or because someone has left, and the instinct is to give it to them: quicker than advertising, cheaper than going to an agency, and it feels like the right recognition for someone who has earned it.
The problem is that instinct is not a reliable guide. In a small firm, the wrong hiring call in either direction can take months to unpick and costs more than founders typically factor in upfront.
What choice are you actually facing?
Framing this as a preference question is where founders go wrong. The real question is what this role actually needs to be filled well, and which route has the better chance of providing it. The internal candidate has structural advantages in some situations. The external market has them in others. Knowing which you are in matters more than having a default position.
Internal recruitment is generally faster. There are fewer candidates to assess, the business already has performance evidence, and the person can move without the extended onboarding an external hire needs. That speed matters when the vacancy is creating pressure on the team and you need the role filled without a prolonged gap.
External recruitment gives you access to a wider candidate pool. That matters most when the role needs skills or experience your current team has not had the opportunity to develop, or when it needs someone who can challenge the firm’s existing thinking rather than continue it. Neither route is universally right, and the choice should follow the role, not a general preference.
When does promoting from within make sense?
Internal promotion works best when the role is primarily about continuity, operational knowledge, and fast handover. That describes a wide range of positions in owner-run businesses: team leads, operations managers, account managers, service delivery, and maintenance roles. The internal candidate already knows your clients, your standards, and how decisions get made in the firm. That standing start shortens the time to useful contribution significantly.
Promoting from within also sends a visible signal. In a small firm where one departure creates a disproportionate workload for everyone else, people notice who gets recognised and who gets passed over. Visible career paths reduce churn, and a reputation for backing your own people makes it easier to attract good candidates when you do need to go outside.
The risk is a stretch promotion. If you are asking someone to carry 40-50% of genuinely new territory, you may be setting them up to struggle while also weakening the role they left. The internal route works when the candidate can handle 70-80% of the new job from day one. The remaining 20-30% is a development curve the business can support. When the gap is larger than that, the calculus shifts.
When does hiring from outside make sense?
External hiring earns its cost when the role requires skills or capabilities your current team has not had the chance to build. New service lines, new markets, a senior role that needs to challenge existing ways of working, digital or technical capability the firm lacks: these are the situations where access to the full candidate market genuinely changes the outcome you can achieve.
It is also the better route when promoting internally would create a domino effect. If the person you promote leaves a role that becomes just as hard to fill, you have exchanged one vacancy for two. External hiring resolves the single gap without triggering a chain.
The cost premium is real and worth knowing. Oyster HR’s data puts initial compensation for external hires around 18% higher than for internal ones. Ascento cites the average cost of a new hire at around £50,000 when recruitment fees, induction time, and the slower early-days productivity are included. That premium is worth paying when the role genuinely needs what the external market has. It is harder to justify for a stable, operational role that a good internal candidate could carry.
What does a bad call actually cost?
A wrong internal promotion typically leaves two roles weakened rather than one: the promoted person struggles, their original position is left underfilled, and colleagues notice. A wrong external hire triggers a different sequence of costs: recruitment fees, salary from day one, onboarding time, and the full cycle again if the fit does not hold. Neither failure is cheap in a small firm, and neither goes unnoticed.
With average hiring costs sitting around £50,000 when you include recruitment, induction, and the slower early-days productivity, the financial case for getting this decision right is plain. The knock-on effects on client continuity, founder time, and team morale are harder to put a number on but often larger in practice than the direct financial hit.
There is also a compliance dimension that smaller firms sometimes underestimate. If you use applicant tracking systems, AI-assisted shortlisting, or automated interview tools in your recruitment process, the ICO is clear that you remain responsible for fair, lawful, and transparent data handling throughout. The Equality Act 2010 requires that promotion and selection decisions are based on documented, objective criteria, whether you are comparing internal candidates, external candidates, or both. Informal decisions are harder to defend if someone challenges the outcome, and the risk is higher in small firms where process rigour is often lower.
What should you ask before you decide?
Before you commit to either route, spend a few minutes with the following questions. They will surface the assumptions you are carrying without realising it, and those assumptions are usually where poor hiring choices begin. The recruitment process that follows is secondary; the framing of the problem is where you need to get it right first.
The first question is whether this role is mainly about continuity or fresh perspective. If continuity, the internal candidate has an advantage. If fresh perspective or new capability, the external market is more likely to deliver it.
Second, if you promote internally, what role becomes vacant behind them? If the answer creates a second vacancy that is just as hard to fill, you may be trading one problem for two.
Third, how long will an external hire take to become fully productive? Factor that into the cost calculation, not just the recruitment fee. An internal candidate is often contributing usefully from week one; an external hire in a complex role can take several months to reach full productivity.
Finally, have you set down the objective criteria you would use to compare candidates regardless of whether they are internal or external? That documentation is your protection under the Equality Act if a decision is later challenged. FCA-regulated firms have additional fitness and propriety obligations for senior roles. And if any part of your process involves AI-assisted tools, check your obligations under ICO guidance before the process starts, not after.
If the questions point in different directions, that is a signal to look more carefully at the role, not to toss a coin. The clarity usually comes from describing exactly what the person needs to do in their first ninety days, and asking honestly which route is more likely to give you someone who can do it.
