To clarify, Proving your pension is covered under Chapter 1 of Part XIV, or Part XIV of the Income and Corporation Taxes Act of 1988, then you're fine. I would not consider a qulified PPP to be a PFIC or trust. HMRC would have to consider the same of an IRA, which I don't belive they do, unless anyone files foreign trust/PFIC equvilent forms with HMRC in respect to their Stateside retirenment account?
Article 18 of the Tax Treaty deals with cross-border pension contributions and is generally intended to remove barriers to the flow of personal services (i.e., employees) that could otherwise result from differences in the US and UK laws regarding the deductibility of pension contributions. This is the first US tax treaty to allow US citizens residing in another country to deduct, for US tax purposes, contributions made to a foreign pension plan.
US Citizens Residing in the UK and Participating in a UK Pension Plan. The Tax Treaty allows US citizens resident in the UK to deduct, for US tax purposes, contributions to a pension plan established in the U.K. This deduction is only available while the US citizen continues to reside in the UK. The US citizen’s deduction is limited to the lesser of (1) the amount deductible in the UK for contributions and benefits under a UK-established pension scheme and (2) the amount that would be deductible in the US for contributions and benefits to a generally “corresponding pension scheme” established in the US. In addition, US citizens will not be taxed by the US as the pension benefit accrues, provided the UK-established pension scheme is a generally “corresponding pension scheme” (as described below).
Corresponding Pension Schemes. The Notes to the Tax Treaty state that “corresponding pension schemes” include:
In the UK: (1) Approved employment-related retirement benefit schemes (for purposes of Chapter 1 of Part XIV of the Income and Corporation Taxes Act of 1988) and (2) Personal pension schemes approved under Chapter IV of Part XIV of such Act).
In the US: (1) Qualified plans under IRC § 401(a), e.g., 401(k) plans, (2) Individual Retirement Accounts (including traditional, SEP and Roth IRAs) and (3) Qualified plans under IRC § 403(a) and (b).