The country we moved to changed its rules after we arrived.

Relocation is asymmetric. Moving takes months; unwinding takes years, because by then there is a lease or a property, a school place, a residence permit tied to a specific status, a company with local substance, and an exit charge waiting in the country left behind. A regime change that would have been merely inconvenient before the move is expensive after it.

Regimes change for reasons that are visible in advance. A special tax status is closed to new applicants or sunset for existing ones under domestic political pressure. EU or OECD review adds substance requirements or minimum taxation. A grey-listing prompts correspondent banks to withdraw, so accounts become harder to hold even where the tax rules are unchanged. A residence programme is suspended, or its renewal criteria tightened, between grant and first renewal.

What tends to be stable is not the headline rate but the structural commitment underneath it: a treaty network, a codified domestic residence test, an established regulator, and functioning correspondent banking. Programmes marketed most aggressively are often the newest and least anchored, and the grandfathering promised at launch is only as durable as the statute that carries it.