◉ Pensions & Investments
ISAs & UK funds (PFIC)
ISAs are not tax-free for US persons. Unit trusts, OEICs, and investment funds inside ISAs are typically PFICs.
Overview
Why this filing matters
ISAs are not tax-free for US persons. Unit trusts, OEICs, and investment funds inside ISAs are typically PFICs.
Note — ISAs reportable as PFICs.
◉ Who this is for
- •US persons with stocks & shares ISAs
- •Clients with UK fund-based investments
✓ What you get
- ✓Per-holding PFIC analysis
- ✓Election strategy (MTM vs. QEF)
- ✓Annual 8621 filings
At a glance
- Key forms
- 8621
- Category
- Pensions & Investments
- Turnaround
- 2–3 weeks once documents are complete
- Filed by
- ACCA-qualified IRS Enrolled Agent
Our approach
Pensions and funds, under the treaty and the code.
UK pensions and investments are where the US–UK treaty does its most useful — and most misunderstood — work. A SIPP may defer US tax under the treaty if the position is claimed properly; an ISA almost never shelters anything from the IRS and often makes things worse by holding PFICs. The difference between the two is a Form 8833 position and a Form 8621 election, not an assumption.
We read each plan and account against both the treaty and the PFIC rules, claim the treaty positions that genuinely apply, and model the PFIC elections (mark-to-market vs QEF) before the gains build up, so your retirement savings are not quietly taxed twice.
- Treaty positions on UK pensions claimed on Form 8833 where they apply
- ISA and fund holdings tested for PFIC status before gains accumulate
- Mark-to-market vs QEF elections modelled rather than defaulted

Our process
How we handle your filing
Four steps from first email to filed return. Fixed fee confirmed in writing before any work begins.
01
Intake
Send us your situation by email or the enquiry form. We come back with the questions we need answered — every source of income for the year, filing history, accounts and entities — and a tailored document list.
02
Review
We analyse your position, flag any cross-border risks, and confirm the scope and fixed fee in writing before any work starts.
03
Prepare
Draft returns and schedules are prepared with plain-English commentary on key positions for your review.
04
File
You sign electronically; we e-file with the IRS / FinCEN and send you the acceptance confirmations for your records.
Pricing
Fixed fees — no surprises
ISA/PFIC strategy review: £350 + VAT. Annual PFIC reporting (Form 8621) is £150 + VAT per holding, with volume discounts for multiple funds.
Prices are indicative starting points and exclude UK VAT, which applies to UK-resident clients only. We quote in writing once we have confirmed every source of income and your filing history for the years involved.
FAQs
Common questions
Related services
Others in Pensions & Investments
UK pension tax planning
How SIPPs and workplace pensions are treated under US law and the US-UK treaty — contributions, growth, and distributions.
Learn more →
US 401(k) / IRA — UK tax treatment
How the UK taxes your US retirement accounts during growth, contributions, and distributions — and how the treaty interacts.
Learn more →
Who this is for
Situations where this filing usually applies
Related reading
Guides from our team on this topic
Ready to get this filed?
Tell us your situation and we’ll reply by email within 2 working days with our questions, then a written scope, fixed fee and document list.