What Separates the Strongest In-House Tax Teams from the Rest?

After years of working exclusively within tax, I’ve had the opportunity to speak with professionals across different industries, countries and stages of their careers. No two tax functions are identical, but certain themes keep surfacing across the market. This article explores the observations that resurface most often in the strongest in-house tax teams I’ve encountered.

Tax functions reflect what the business believes is worth investing in

Most tax professionals experience tax through the organisations they work for, which is entirely natural. What I’ve found through years of specialising in tax is that effective tax functions come in many different forms. The regulations may be broadly consistent, but businesses aren’t. Different leadership teams, investors, growth strategies and attitudes towards risk all influence how tax is viewed within an organisation.

One thing I’ve noticed repeatedly is that tax functions are rarely built solely around what a business needs. More often, they’re built around what the business believes is worth investing in. In some organisations, those two things are closely aligned. In others, there’s a noticeable gap between what the tax function believes the business needs and what the business is prepared to fund.

That’s one of the reasons similar-sized organisations can end up with very different tax functions, and why hiring decisions can look so different from one business to another. Some organisations invest ahead of need. Others invest once pressure starts to build. In some cases, a resignation, a transaction or an unexpected challenge exposes a weakness that had existed for years but wasn’t visible while everything was running smoothly.

Bringing tax in-house isn’t really about adviser fees

One assumption I still come across from time to time is that bringing tax in-house is primarily about reducing external advisory spend. In reality, the strongest organisations tend to view it very differently.

Building an in-house tax function doesn’t remove complexity, and it certainly doesn’t eliminate the need for external advisers. Significant transactions, specialist technical issues and niche areas of expertise will often continue to require outside support. What an in-house team changes is where tax sits in the decision-making process. When tax is embedded within the business, risks are identified earlier, implications are better understood, and important decisions can be made with a clearer view of the consequences. The value isn’t simply in reducing fees. More often, it’s in avoiding problems, improving decisions and ensuring tax isn’t an afterthought when the business is growing, changing or investing.

Hiring conversations reveal a lot about a tax function

Recruitment processes often reveal more about a tax function than the job description ever will. A business might say it’s hiring because a key individual has resigned, but the real issue is frequently that too much capability, knowledge or decision-making responsibility had accumulated with one person. Everything works perfectly well until they leave, at which point the organisation discovers just how much of the function depended on an individual rather than a team.

It’s a situation that comes up surprisingly often. For years, succession planning appears to be in place. Then somebody leaves and it becomes clear that succession planning was really just hoping that person stayed.

Experienced individuals remain hugely important, of course, but capability is developed throughout the team. In the stronger functions, knowledge is shared, responsibility is distributed, and people are given opportunities to broaden their experience before they’re needed in more senior roles.

What’s interesting is that some of the best Heads of Tax I’ve worked with don’t view succession planning purely as a defensive exercise. They understand that if they’re developing people properly, not everyone will stay. At some point, a talented individual may simply outgrow the opportunities available within the team. The next step might be a leadership role elsewhere, a broader position, or an opportunity that arrives at exactly the right moment in their career. Those departures can be disappointing, but they’re not necessarily a sign that something has gone wrong. In many cases, they’re evidence that somebody has been developed successfully.

The challenge is creating an environment where talented people continue to grow while the next generation of talent develops behind them. The best tax leaders seem to have an instinct for this. They can often see when somebody is approaching that next stage before the individual fully recognises it themselves — they’ve watched their confidence grow, seen their responsibilities expand, and understand when they’re ready for a bigger challenge.

That’s why succession planning isn’t really about preparing for somebody to leave. It’s about making sure the function continues to thrive when they do. When somebody eventually moves on, there is disruption, but not instability. From a recruitment perspective, that’s often one of the clearest indicators of a mature and well-developed tax function.

The most influential teams don’t wait for the tax question

What separates many tax functions isn’t technical expertise. It’s when tax enters the conversation. In some organisations, tax becomes involved once a direction of travel has already been agreed. In others, tax is involved while options are still being explored. I’ve never thought that difference was explained by technical capability alone — there are highly capable tax professionals in both situations. More often, it comes down to credibility.

Most significant business decisions don’t begin as tax discussions. They’re conversations about acquisitions, growth, investment, restructuring, financing or transformation. The tax functions with the greatest influence tend to be those that have built enough trust for people to want their input before a course of action has been chosen. That trust is rarely built through technical knowledge alone. More often, it’s earned through sound judgement, pragmatism and a reputation for helping the business navigate decisions rather than simply reviewing them afterwards.

Over time, tax stops being seen purely as a function that approves decisions and starts becoming one that contributes to them. It’s a subtle shift, but in my experience it’s one of the biggest differences between a tax team that is respected and a tax team that is genuinely influential.

Capacity isn’t always a headcount issue

Almost every Head of Tax I speak with is managing competing demands. That’s hardly surprising: the scope of most tax roles looks very different from ten years ago, while resources haven’t always expanded at the same pace.

What has always interested me is that the most effective functions aren’t necessarily the ones doing the most. They’re often the ones with the clearest understanding of where they add value. The tax leaders with the greatest impact are usually very deliberate about priorities. They understand which issues require deep involvement, which activities create the greatest value, and where the business most needs their expertise. In practice that’s much harder than it sounds, because everything tends to arrive with a sense of urgency attached.

In many organisations, creating capacity isn’t solely about adding another person to the team. It’s about making conscious decisions about where time, attention and expertise should be directed. The most successful functions are clear about what matters most and prepared to make difficult decisions about where their time is best spent. That clarity often creates space for more meaningful contribution elsewhere.

In-house tax is evolving faster than many people realise

If there’s one change I’ve noticed more than any other in recent years, it’s this. Historically, much of the focus of an in-house tax function centred on compliance, reporting and managing relationships with external advisers. Those responsibilities remain important. What has changed is the expectation of what an in-house function can contribute beyond them.

As compliance becomes increasingly automated, centralised or outsourced, in-house tax professionals are often being drawn closer to major business decisions rather than further away from them. I’m seeing more tax teams involved in transactions, transformation programmes, international expansion, operating model changes and broader strategic discussions. Businesses increasingly want tax involved earlier because they recognise the value of understanding the implications before key decisions become difficult to change.

I think this is one of the reasons the conversation about moving from practice into industry has become more interesting. One assumption I occasionally hear is that moving in-house means doing broadly the same work for a different employer. The reality is often quite different. Technical capability remains fundamental, but increasingly it’s the starting point rather than the differentiator. The in-house professionals who thrive are often those who enjoy operating at the intersection of technical capability, commercial decision-making and business strategy. They want to understand not only the tax answer but also the context surrounding it and the impact it will have on the organisation.

Final thoughts

When people talk about high-performing tax teams, the conversation often gravitates towards technology, structure, reporting lines or headcount. Those things matter. But when I think about the tax functions that stand out, they’re rarely the factors I remember most.

What stays with me is how resilient those teams tend to be. They aren’t thrown off course when key individuals leave, they’re involved in important business discussions earlier, and they’re clear about where the function can create the greatest value. Technical capability remains essential — it always will — but it’s increasingly viewed as a baseline expectation rather than a differentiator. What distinguishes one function from another is how effectively that capability is embedded within the business.

The strongest in-house tax teams I’ve encountered aren’t valued simply because they understand tax. They’re valued because they help businesses make better decisions, navigate complexity with confidence and address issues before they become problems. More businesses are looking to their tax teams for insight, judgement and support in decision-making, while compliance activity becomes increasingly automated, centralised or outsourced. In many organisations, the value of the in-house function is no longer measured solely by what it delivers itself, but by how effectively it helps the business navigate change, manage risk and make informed decisions.

From where I sit, that’s one of the most significant shifts taking place across the profession. And it’s often what separates the strongest teams from the rest.