US Tax Preparation for American Expats: Fees & Timeline

US tax preparation for American expats in London typically runs from roughly £1,200 to £3,500 plus VAT for a single complex year, and from roughly £4,000 to £12,000 plus VAT for a complete three-year IRS Streamlined catch-up with six years of FBARs. Budget eight to sixteen weeks of preparation, then six to twelve months of IRS processing.

That range is wide for a reason, and the reason is not the return itself. A US federal return for an American who earns a salary in London and holds nothing else is a modest piece of work. The fee climbs when the affairs behind the return are those of a genuinely wealthy filer: shares in a UK limited company, a portfolio of UK-domiciled funds, a let property in Zone 2, RSUs vesting on a US parent's schedule while payrolled in the UK, and a self-invested personal pension nobody has ever valued for US purposes. Each of those is a separate schedule, and in a multi-year catch-up each one multiplies by the number of years in scope.

This guide sets out what the money actually buys, stage by stage, and how long each stage really takes — including the parts of the timeline that sit with your UK banks and your former employer's share plan administrator rather than with your accountant. At Jungle Tax we quote catch-up engagements on a fixed fee after a scoping review precisely because the drivers below are knowable in advance.

What does US tax preparation for American expats actually cost in 2026?

The published market splits into three broad bands. Online-first US providers advertise flat fees in the region of $500 to $700 for a straightforward federal return covering Form 1040 with either the foreign earned income exclusion or the foreign tax credit, and packaged Streamlined offerings in the region of $1,750 to $3,000. London-based US-qualified firms typically start higher — a base Form 1040 fee from around £900 plus VAT is a common published minimum — and price by complexity from there.

Neither band is wrong. They serve different filers. The packaged price assumes a salaried filer with a handful of bank accounts. It stops describing reality the moment your return needs a Form 5471 for a UK company, a Form 8621 for each UK fund holding, a Schedule E for a let property with its own depreciation history, and a Form 1116 that has to be re-cut across multiple income baskets. The honest way to read a headline price is to ask what it excludes.

Indicative fee bands for a London-based filer

• Simple year — UK employment income only, PAYE, a current account and a cash ISA. Form 1040, Form 1116 or 2555, FBAR. Roughly £900–£1,400 plus VAT.
• Moderate year — employment plus a UK rental property, a general investment account, a workplace pension. Adds Schedule E, Form 8938, foreign tax credit basket work. Roughly £1,500–£2,500 plus VAT.
• Complex year — shares in a UK limited company, PFIC-exposed fund holdings, RSU or option vests with dual-country sourcing, multiple properties, a SIPP with treaty positions. Roughly £2,500–£5,000 plus VAT, and higher where a controlled foreign corporation is in play.
• Three-year Streamlined catch-up — three federal returns, six FBAR years, the Form 14653 certification narrative, plus every schedule above repeated per year. Commonly £4,000–£12,000 plus VAT, occasionally more where fund holdings are numerous.

Two structural points that generalist pricing pages omit. First, VAT: professional fees supplied by a UK-established firm to a UK-resident private individual carry UK VAT at the standard rate, so a £5,000 quote is a £6,000 cash cost. A US-established provider billing you in dollars generally does not add UK VAT, which is part of why headline US prices look lower than they are once scope is matched. Second, the fee is not the only cost — a catch-up frequently produces a US balance due with interest, and separately a UK disclosure may carry its own tax, interest and penalty.

Which features of a wealthy filer's affairs drive the fee up?

Fee inflation in cross-border work is almost never about the volume of income. It is about the number of distinct US information returns your facts trigger, and whether the underlying data exists in a usable form. These are the drivers we see most often in London engagements.

Shares in a UK limited company

If you own or control an interest in a UK company, you are likely into Form 5471 territory — a substantial information return with multiple schedules whose content depends on your ownership category. Where the company is a controlled foreign corporation, GILTI computations and a possible section 962 election follow, and the analysis has to be run for each year in scope. A single Form 5471 is commonly priced from around £1,000 plus VAT per company per year, so a three-year catch-up carries it three times. The IRS sets out the filing categories on its Form 5471 guidance page. Getting the category wrong is expensive: the statutory penalty for a late or incomplete Form 5471 starts at $10,000 per form per year.

UK funds, ISAs and investment accounts

This is the single largest and most under-priced driver. Nearly every UK-domiciled OEIC, unit trust, investment trust and ETF is a passive foreign investment company for US purposes. Each holding, in each year, is potentially its own Form 8621 with its own excess-distribution computation, which requires the full purchase history and reinvested-income history of the holding — not just its year-end value. A stocks and shares ISA holding a dozen funds is not one line on a return; it is up to twelve forms per year, and a three-year catch-up multiplies that again. Firms commonly price PFIC work per fund per year, and this is where a quote moves from four figures to five. Reducing the number of PFIC positions before a catch-up begins is frequently the highest-return decision a client makes.

RSU and option vests at a US-listed employer

Equity compensation earned partly while US-resident and partly while UK-resident has to be apportioned between the two countries by workday, then reconciled against what UK PAYE actually withheld at vest and what the US employer reported. The paperwork lives in a share plan portal that often shows a US-centric view only. Rebuilding a defensible sourcing schedule across several vest events and several years is genuine analytical work, and it is usually the item that adds the most unbilled hours when it is not scoped up front.

UK rental property

A let property in London needs a US Schedule E with its own basis and depreciation schedule maintained in dollars from the date of acquisition, which is a different computation from the UK property income figure HMRC sees. Mortgage interest treatment diverges, the UK finance cost restriction has no US analogue, and a foreign exchange gain can arise on repaying a sterling mortgage. If you have never depreciated the property for US purposes, a catch-up may require a change of accounting method rather than a simple correction.

UK pensions

A SIPP or workplace scheme needs valuing for FBAR and potentially Form 8938, and its treatment relies on the US–UK treaty. Employer contributions, member contributions and internal growth each raise their own questions. Where a pension holds funds directly rather than through an insured wrapper, the PFIC question resurfaces. Pension work rarely adds enormous fees on its own, but it consistently adds weeks to the timeline because scheme administrators are slow to produce historic valuations.

Data quality

The invisible driver. Where a client arrives with clean, complete records in a single folder, we price at the bottom of the band. Where the engagement begins with reconstructing eight years of transaction history from partial statements, it prices at the top. Everything in the records-gathering section below is, in effect, a fee-control exercise.

How long does each stage of a multi-year catch-up take?

Clients almost always underestimate the front half of the timeline and overestimate the back half. Preparation is not the bottleneck. Documents are.

Stage 1 — Scoping and route selection (1 to 2 weeks)

Before anything is prepared, the route has to be chosen: the Streamlined Foreign Offshore Procedures, a delinquent FBAR submission, a limited catch-up of a small number of years, or — where conduct was not non-willful — a formal voluntary disclosure. The Streamlined route requires a certification that the failure to file was non-willful and, for the foreign version, that you meet the non-residency test. The IRS publishes the eligibility conditions in its Streamlined Filing Compliance Procedures guidance. This stage also fixes the fee, because it establishes how many years, how many entities and how many fund positions are in scope. Our IRS Streamlined filing team handles this as a discrete first phase.

Stage 2 — Records gathering (2 to 10 weeks, and the real bottleneck)

This stage runs on other people's service levels, not yours. Realistic elapsed times we plan around:

• UK bank statements beyond the online window — most retail banks show 12 to 24 months online and charge for archived statements; requests covering six years commonly take two to six weeks and sometimes arrive as scanned PDFs that need manual extraction.
• Investment platform transaction histories — usually quicker, one to three weeks, but consolidated tax certificates rarely go back six years and reinvested income often has to be pulled fund by fund.
• Pension scheme valuations at historic dates — three to eight weeks is normal. Start these on day one.
• Share plan records — vest-by-vest data from a US parent's administrator, plus UK payroll records showing what was actually taxed at vest. Two to four weeks, longer if you have changed employer.
• Company accounts and shareholder registers — fast if your UK accountant is engaged, slow if the company has changed advisers.
• HMRC records — your personal tax account and, where needed, records requested from HMRC. Allow two to four weeks.

Every one of these can be started in parallel on day one. Clients who do so routinely finish the whole engagement a month earlier than clients who wait to be asked item by item.

Stage 3 — Preparation and review (4 to 8 weeks)

Once records are complete, a three-year package with the complexity described above typically takes four to eight weeks through preparation, technical review and your own review. A single straightforward year can be turned around in two to three weeks. The order matters: where you are claiming foreign tax credits, the US computation depends on UK tax being settled for the corresponding period, so the UK workstream must be at least provisionally resolved first.

Stage 4 — Filing (1 to 2 weeks)

Streamlined packages are filed on paper to a designated IRS address, with Form 14653 attached and the required annotation on each return. FBARs are filed electronically through the FinCEN BSA system with the Streamlined reason stated. Paper filing means postal transit and no instant acknowledgement, which is one reason the perceived timeline stretches.

Stage 5 — IRS processing (6 to 12 months, sometimes longer)

The IRS does not issue an acceptance letter for a Streamlined submission. What you see instead is account activity: transcripts updating, adjustment notices such as CP21 or CP22, and a balance-due notice where tax and interest arise. In practice, roughly twelve months of silence following processing is the signal that a submission has been accepted without examination. Correspondence asking for clarification is common and is not, by itself, a bad sign.

US and UK stages side by side

Stage	US / IRS	UK / HMRC
Tax year	Calendar year, 1 January to 31 December	6 April to 5 April, so UK payroll and dividend data must be re-cut to the US year
Catch-up route	Streamlined Foreign Offshore Procedures — 3 years of returns, 6 years of FBARs, Form 14653	Worldwide Disclosure Facility or amended returns, with years determined by behaviour
Typical years in scope	3 income tax years, 6 FBAR years	4, 6 or up to 20 years depending on whether the failure was careless or deliberate
Filing deadlines	15 April, automatic extension to 15 June for filers abroad, 15 October on election	31 January for online filing, with payments on account due 31 January and 31 July
Penalty exposure on catch-up	No penalty under Streamlined if eligible; information-return penalties otherwise	Penalties as a percentage of tax, reduced for unprompted disclosure and full co-operation
Processing after filing	6 to 12 months, no acceptance letter issued	Typically 3 to 6 months to an agreed offer under a disclosure
Principal fee driver	Number of information returns per year — 5471, 8621, 8938, 3520	Number of income sources and whether records support the return

Should the UK side run first, second or in parallel?

In parallel, with the UK position resolved marginally ahead. The reason is mechanical: your US foreign tax credit claim on Form 1116 depends on UK tax that is paid or accrued, so an unresolved UK liability leaves the US computation provisional. If a UK disclosure later changes the UK tax for a year, the US return for that year may need amending — and amending a Streamlined year after submission is awkward.

Where a client has both missed US returns and unfiled UK returns, we sequence the UK disclosure to reach an agreed figure first, using HMRC's Worldwide Disclosure Facility where appropriate, then finalise the US package against settled numbers. The additional UK workstream typically adds £1,500 to £4,000 plus VAT depending on years and complexity, and is handled by our UK tax team alongside the US preparation rather than sequentially.

What is included in a properly scoped fixed fee — and what is not?

Ask for the inclusions in writing. A well-constructed catch-up fee should cover the scoping review, preparation of each federal return and its schedules, all FBAR years, the Form 14653 narrative, one round of client review comments, filing, and responding to routine IRS correspondence arising directly from the submission.

Items commonly excluded, and reasonably so: state returns where a state filing obligation persists; reconstruction of records where third-party data cannot be obtained; PFIC computations beyond an agreed number of holdings; entity-level UK accounts preparation; representation in an examination; and any planning work, which is a separate discipline from preparation. Ask specifically how additional PFIC positions and additional entities are priced, because those are the two items most likely to move after work begins.

Five ways to reduce the fee without reducing the quality

• Consolidate fund holdings before the engagement starts, understanding that a disposal has its own tax consequences — take advice on the ordering first.
• Request archived bank and platform statements on day one, before your adviser asks. This alone often removes a month from the timeline.
• Deliver data in one structured pass rather than in a trickle of emails. Fragmented delivery is the most common cause of a fee rising above the estimate.
• Close dormant accounts — but only after the FBAR lookback period is covered, because a closed account still has to be reported for the years in which it existed.
• Use one firm for both sides. Running a US preparer and a separate UK accountant who never speak to each other reliably costs more in duplicated work than a single joined-up engagement.

What happens if you simply keep filing forward instead?

Filing the current year and ignoring the history is the most expensive form of economy in cross-border tax. The IRS confirms that the filing obligation for citizens abroad is unconditional in its guidance for US citizens and resident aliens abroad, and the statute of limitations does not begin to run on an unfiled return at all. Meanwhile, an information return that is never filed — a 5471, an 8938, a 3520 — can leave the entire return open to assessment. FBAR penalties are inflation-adjusted annually and, even in the non-willful band, exceed $16,000 per violation. Streamlined relief also depends on the IRS not having contacted you first, which means the option is available only while it remains voluntary. You can model the exposure with our FBAR penalty calculator.

A worked example: a partner-track executive in London

Consider a US citizen who has lived in London for nine years, has never filed a US return, earns a substantial UK salary, holds RSUs in a US-listed employer that vest annually, owns a flat in Islington that has been let for four years, holds a stocks and shares ISA with seven fund positions and a general investment account with four more, and has a SIPP from a previous employer.

Scope: three federal returns, six FBAR years, Form 14653, Schedule E for four let years, Form 8938 for each year, foreign tax credit computations in more than one basket, RSU sourcing across three vest events per year, and PFIC analysis on eleven fund positions across three years. That is a substantial engagement — realistically in the £8,000 to £14,000 plus VAT range once PFIC work is priced properly — and eleven to eighteen weeks of elapsed time before filing, driven principally by the SIPP valuation and the archived statement requests.

The same person, having consolidated the ISA into two positions and holding clean records, would sit materially lower and finish several weeks sooner. The scoping call is where that difference gets identified, which is why we do not quote before it.

How do you choose between a US online provider and a London specialist?

Match the adviser to the complexity, not to the headline price. A packaged US provider is a rational choice for a salaried American with a current account and no investments. It is the wrong choice when the return turns on the UK–US interaction: treaty positions on a SIPP, GILTI on a UK trading company, the sourcing of equity compensation across a relocation, or the UK disclosure that has to be settled before the US credit can be claimed. Those are the points at which generalist preparation quietly produces returns that are filed but wrong — and a wrong Streamlined submission is far more expensive to unwind than a well-prepared one was to produce. Our approach to the combined position is set out under cross-border tax, and further reading sits in our guides library.

One further practical filter: ask whether the firm prepares both the US return and the UK Self Assessment, and whether the same team sees both. Where they do, the foreign tax credit position is reconciled once rather than negotiated between two firms who each assume the other has it covered.

Ready to know what your position actually costs?

A multi-year catch-up is a defined project with a knowable price and a knowable end date — but only once someone has looked properly at the entities, the fund positions and the years genuinely in scope. We scope first, quote a fixed fee second, and file third, so you are never presented with a bill that grew. If you are an American in London with unfiled years behind you, contact our cross-border team for a confidential consultation. Nothing is filed without your approval, and you will leave the first conversation knowing the range, the sequence and the timetable that apply to your affairs.