Before you leave the NHS, do the maths.

Outside CCR London, I overheard a conversation that stopped me in my tracks.

Two people, who appeared to be GPs, were discussing the prospect of building a career in medical aesthetics.

The woman seemed to have already established a practice. The man sounded as though he was considering his options.

Her advice was striking.

He needed to be "damn sure" he could make enough money from aesthetics to compensate for what he'd otherwise receive through his NHS pension.

Not simply enough to replace his salary.

Enough to make the wider financial trade-off worthwhile.

His response was equally interesting.

He suggested he'd only need a couple of clients a week.

And there, in the space of a few sentences, was a question I think deserves far more attention in conversations about starting an aesthetics business.

What, exactly, are you trying to build?

The same qualification. Three very different businesses.

It's tempting to think of moving into medical aesthetics as a single career decision.

But the commercial reality depends entirely on what someone wants the business to achieve.

Consider three possible ambitions.

1. A little extra income

A clinician intends to remain in the NHS and treat a handful of private patients each week.

The objective might be an additional £1,000 a month, some professional variety, or simply the opportunity to develop another area of practice.

This business needs to be financially worthwhile, manageable and compatible with existing commitments.

It doesn't necessarily need to become a full-time enterprise.

2. A portfolio career

A clinician wants to gradually reduce NHS sessions and replace some of that income with private practice.

Now the calculation changes.

The business must generate sufficient sustainable returns to justify reducing established employment income, while accommodating the additional time, costs and responsibilities of self-employment.

And the timing matters. What looks attractive at full capacity might be considerably less attractive during the first year.

3. A substantial career replacement

A clinician ultimately wants private practice to replace the economic value of a significant NHS career.

This is a different proposition altogether.

It requires much more than a few profitable treatment appointments.

It requires a commercially viable business capable of producing sufficient, sustainable returns after costs, tax, investment, downtime and the risks associated with running a private practice.

And that brings us back to the woman's warning.

Your NHS salary isn't the whole comparison.

When people talk about replacing employment income with self-employment, they often focus on the most visible number.

Salary.

But a salary is only one component of what an established career provides.

Depending on individual circumstances, an NHS career may also offer pension benefits, paid annual leave, sick pay, greater income predictability, professional development opportunities and a degree of employment security.

Private practice has its own attractions, of course.

Autonomy. Flexibility. Greater control over the services you offer and the direction of your career. Potentially, the opportunity to build a valuable business over time.

But it also introduces costs and risks that don't appear in a simple comparison of salary against treatment revenue.

Premises. Insurance. Equipment. Consumables. Marketing. Administration. Training. Compliance. Cancellations. Quiet periods.

Not to mention the hours spent running a business rather than treating patients.

Revenue is not profit. Profit is not take-home pay. And take-home pay is not the entire economic value of a career.

That's why the question shouldn't simply be:

Can I earn as much in aesthetics as I earn in the NHS?

A more useful question might be:

What would my private practice actually need to produce before reducing or leaving NHS work becomes economically worthwhile for me?

And the answer will be different for almost everyone.

A couple of clients a week might be absolutely enough.

This is the other side of the conversation that interested me.

The man's suggestion that he might only need a couple of clients each week wasn't necessarily naive.

Perhaps he'd already considered the numbers. Perhaps he wanted a modest supplementary income. Perhaps he had no intention of reducing his NHS commitments.

I couldn't know from a conversation overheard outside a conference.

But it illustrates why defining the purpose of a business matters before making decisions about its structure, services or marketing.

Someone seeking modest additional income may not need extensive premises, a broad treatment portfolio or an ambitious patient acquisition strategy.

Someone building towards a full career replacement may eventually need all sorts of things that would be unnecessary, even counterproductive, for the first person.

Same industry.

Potentially similar qualifications.

Entirely different commercial requirements.

And yet both might receive exactly the same advice about what equipment to buy, which treatments to offer and how much to spend on marketing.

That's where I think we need to ask better questions.

Start with the destination, not the treatment menu.

Before choosing a clinic location, investing in equipment or deciding how to attract patients, I'd encourage any clinician considering private practice to answer two questions.

What role do you actually want this business to play in your life?

And:

What does it need to deliver financially, and over what timescale, for that ambition to make sense?

Only then can you begin evaluating the market opportunity, likely patient demand, treatment economics, capacity, investment requirements and commercial risks.

It's also perfectly reasonable for those ambitions to change.

A small supplementary practice might grow into something more substantial. Equally, someone who initially imagines leaving the NHS might discover that a portfolio career offers a better balance of income, security and personal satisfaction.

Neither outcome is inherently better.

The point is to make the decision deliberately.

The diagnosis

Before you ask whether your aesthetics business can make money, establish what you actually need that money to do.

Because building a business that generates £1,000 a month in additional income and building one that can economically replace an established NHS career are not simply different-sized versions of the same challenge.

They're different commercial decisions.

And those decisions deserve proper consideration before the spending begins.

Strategy before spend. Always.

This article is a commercial observation prompted by an overheard conversation, not a representative finding about NHS clinicians. Individual decisions about NHS employment, pensions and private practice should be informed by personalised financial, pension and professional advice.