A striking example is a policy offered by Old Mutual International (OMI), a subsidiary of London-listed Quilter,
which pays out a lump sum of millions of pounds to heirs in Singapore inheriting property in Britain,
allowing them to foot the inheritance-tax bill without needing to sell the properties.
But this policy at least has a large cash payout; many others are "wrappers" that simply fold existing assets into insurance payouts.
Reasons to buy range from wealth protection—from high taxes, government expropriation or succession squabbles—to tax arbitrage.
In many countries the proceeds of a life-insurance policy attract less tax than a direct inheritance.
Unhappily for Manx firms, these products are sold with hefty commissions. Some of their brokers in far-flung countries charge 6-7% of a policy's value.
Though that is similar to commissions in onshore jurisdictions—around 6% in Ireland, for instance—
onshore life insurance is mainly about death benefits, annuities and to an extent savings.
A better comparator for Manx products is financial advice, where commissions have been slashed.
In Britain financial advisers must charge retail investors fixed fees rather than commissions, to avoid conflicts of interest.
Business might shift to avoid the new rules. One Manx official worries about competition from the British Virgin Islands.
Or clients boggling at the newly revealed fees may switch to a different sort of vehicle for asset protection,
for example the trusts in which Jersey and Guernsey, also Crown dependencies, specialise.
The Isle of Man will still benefit from a stable legal environment and specialist talent.
It already offers some products that rely on neither Britain's tax forbearance nor rich individuals elsewhere.
Notably, the Manx operations of Zurich Insurance, a global insurer, focus on life-insurance and pensions schemes for the employees of multinational firms.
But the island's financial industry will have to diversify: to new types of customers such as corporations, for example, or to products that are less dependent on brokers.