Owner of a US Health Savings Account, is tax due if a UK resident?

[Menisco]

I am a US/UK dual national residing in the US with intent to move to the UK in the future. I have about $6500 in a Health Savings Account (HSA). The dual taxation treaty between the US and the UK states that pension funds, IRA's, ISA's and the like continue to grow tax-deferred no matter if the owner resides in the US or the UK. What about my HSA? Would tax be due on any interest, dividends or gains within this account?

A Health Savings Account is a US savings and investment account which grows free of US income tax on interest, gains and dividends. It can contain cash, shares, bonds or unit trusts. Money from this account can only be used to pay for health care expenses. US income tax is due if money is withdrawn for any other purpose, with an additional 20% penalty if under age 65. Aside from this health care expense provision, it functions similar to a retirement account.

The HSA is a strange creation, a vehicle to help Americans deal with the high cost of health care, and often paired with low-premium, high-deductible health insurance. Because of that, I suspect that UK tax law does not have much to say about it. Has anyone had any experience dealing with tax for a UK resident who owns a HSA based in the US?

Thank you.

[DavidTreitel]

I see no UK tax deferral. You'd want to think if the sale of funds in the HSA might give rise to offshore income gains.