For much of the past few decades, international tax planning operated on an implicit assumption: that information asymmetry between a taxpayer's structure and a given tax authority's visibility into it was a permanent and exploitable feature of the system. Structures were built, in part, on the reasonable expectation that no single authority could see the whole picture. That assumption has been dismantled almost completely over roughly the last ten to fifteen years, and the planning discipline built on top of it has had to change just as completely.
The mechanics of that shift are now familiar to anyone working in the field — automatic exchange of information between tax authorities, base erosion and profit shifting reforms, beneficial ownership registers, substance requirements that ask not just where a structure is registered but where decisions are actually made and where genuine economic activity actually happens. What's less often discussed is how thoroughly this changed the actual skill being practised. A discipline that used to reward finding gaps in visibility now rewards something closer to its opposite: building structures that are fully visible and still defensible.
Substance stopped being a checkbox
Fifteen years ago, "substance" in an international structure often meant a registered address, a local director, and a modest set of paper formalities — enough to satisfy a fairly mechanical test. That bar has risen substantially. Authorities now look for genuine indicators of real activity: where strategic decisions are actually debated and made, where the people with real authority over a structure actually spend their time, whether a local presence reflects genuine operational reality or just a filing requirement satisfied at minimum cost.
That shift has been, on balance, a healthy one for the field, even though it has made the work considerably more demanding. Structures that would have passed scrutiny on paperwork alone a decade and a half ago now need to reflect something closer to operational reality, which means tax planning has become inseparable from the genuine way a business or a family actually organises itself, rather than a layer applied on top of it afterward. Good advisory work in this space increasingly starts with how things actually function, not with what the optimal structure on paper would look like in isolation.
Defensibility has replaced aggressiveness as the relevant metric
The practical consequence of greater transparency is that a structure's value is now judged less by how much tax exposure it minimises in a best-case scenario and more by how well it holds up under genuine scrutiny — because genuine scrutiny is now a realistic possibility rather than a remote one. That changes the kind of advice that's actually useful. The most valuable guidance in this field today tends to sound less like "here is an aggressive position to take" and more like "here is a position you can fully explain, with full documentation, to an inquisitive tax authority, and still sleep well afterward."
That's a quieter, less dramatic version of international tax planning than the one that existed when information asymmetry was still the operating assumption. It is also, after watching the field operate under both paradigms, a considerably more durable one.