Q: Is Streamlined cheaper than not coming forward?

Almost always. Outside a disclosure programme, penalties for unfiled FBARs and information returns can reach thousands of dollars per account or per form (forms like 5471 and 3520 carry $10,000-plus penalties). Streamlined trades that exposure for a penalty-light catch-up — but it generally stops being available once the IRS contacts you, so acting first matters.

How much does IRS Streamlined Filing cost?

It has three parts: the IRS penalty (0% for the Foreign procedure that most US expats in the UK qualify for; 5% of foreign assets for the Domestic procedure), any actual tax you genuinely owed (often low after the Foreign Tax Credit/FEIE), and a professional fee that depends on complexity. For a typical UK-based American, the penalty is nil and the main cost is the preparation fee.

What is the difference between Streamlined Foreign and Domestic?

The Streamlined Foreign Offshore Procedures (for taxpayers meeting a non-residency test — most Americans genuinely living in the UK) carry a 0% miscellaneous offshore penalty. The Streamlined Domestic Offshore Procedures (for those physically in the US) carry a 5% penalty on the highest year-end value of unreported foreign assets. Qualifying as 'foreign' is what makes the catch-up inexpensive.

What do I have to file under Streamlined?

Three years of amended or delinquent income tax returns, six years of FBARs (FinCEN Form 114), and a signed non-wilful certification (Form 14653 for the Foreign procedure). Depending on your assets you may also need PFIC (8621), foreign company (5471), partnership (8865) or foreign trust (3520) forms, which add to the work and the fee.

Will I owe US tax under Streamlined?

Often little or none. The Foreign Tax Credit and FEIE typically eliminate US tax on UK-taxed income such as salary, so many expats owe little. Tax tends to arise only on income the credits don't fully cover, such as certain investment income. Any tax due is money you genuinely owed, plus interest — not a penalty for using the programme.

If you are an American who has fallen behind on US taxes while living in the UK, the IRS Streamlined Filing Compliance Procedures are usually the way back — and for many expats the IRS penalty is genuinely zero. But 'no IRS penalty' is not the same as 'free', and the question everyone asks is fair: what does Streamlined actually cost? This guide breaks the cost into its real parts — the IRS penalty (often nil), any tax due, and the professional fees — and explains what makes one case cheaper than another.

The two streams: Foreign vs Domestic

Streamlined has two versions, and which one you use is the single biggest driver of the penalty cost. The Streamlined Foreign Offshore Procedures (SFOP) are for taxpayers who meet a non-residency test — broadly, Americans genuinely living abroad, which most US expats in the UK satisfy. The Streamlined Domestic Offshore Procedures (SDOP) are for those who were physically in the US. The difference is dramatic: SFOP carries a 0% miscellaneous offshore penalty, while SDOP carries a 5% penalty on the highest year-end value of your unreported foreign financial assets.

Cost part 1: the IRS penalty (often zero)

For most Americans in the UK who qualify for the Foreign procedure, this is the good news: the miscellaneous offshore penalty is nil. You are not paying a penalty to the IRS for coming forward — the programme is deliberately designed to encourage non-wilful taxpayers to get compliant. For the Domestic procedure, the 5% penalty is calculated on the highest aggregate year-end balance of your foreign accounts and assets over the covered period, which can be substantial for someone with a UK pension or investments. Confirming you qualify as 'foreign' is therefore the most valuable single step.

Cost part 2: any actual tax due

Streamlined requires you to file (or amend) the last three years of tax returns and pay any tax owed on them, plus interest. For many expats this tax is low or nil, because the Foreign Tax Credit and the FEIE wipe out most or all US tax on UK-taxed income. Where tax does arise, it is usually on income the credits do not fully cover — certain investment income, or years with US-source income. This is real tax you would have owed anyway, not a penalty, so it is best thought of as 'catching up' rather than a cost of the programme.

Cost part 3: the professional fees

For most people, the professional fee is the main out-of-pocket cost — and it varies with complexity. A Streamlined submission is not a single form; it is three years of returns, six years of FBARs, and a signed non-wilful certification (Form 14653 for the Foreign procedure) that has to tell your story accurately and persuasively. Simple cases — employment income, a few bank accounts — cost less; cases with rental property, investments, PFICs, a business or a pension drawdown cost more because each adds forms and analysis.

Three years of amended or delinquent income tax returns.
Six years of FBARs (FinCEN Form 114).
The non-wilful certification statement (Form 14653 — Foreign).
Any supporting forms: PFIC (8621), foreign company (5471), foreign partnership (8865), foreign trust (3520).

What drives the price up or down

The number of returns is fixed at three, so what moves the fee is what is inside them. The big cost drivers are foreign investments that are PFICs (each fund can mean a separate Form 8621), ownership of a UK company (Form 5471) or partnership (Form 8865), rental properties, and complex pension arrangements. The simplest cases — a salaried American with a current account and an ISA they are willing to clean up — sit at the low end. Knowing your asset mix is the fastest way to get an accurate quote.

Why the certification matters so much

The non-wilful certification is the heart of a Streamlined submission, and it is where experience earns its keep. You are certifying, under penalty of perjury, that your failure to file was non-wilful — due to negligence, inadvertence, or a good-faith misunderstanding rather than a deliberate attempt to evade. A weak or careless certification can undermine the whole submission and even invite scrutiny. Getting the facts, tone and detail right is not box-ticking; it is the part that protects you, which is why it should never be rushed or copied from a template.

Streamlined vs doing nothing

Compared with the alternative, Streamlined is usually a bargain. The penalties for unfiled FBARs and information returns outside a disclosure programme can dwarf any Streamlined fee — FBAR penalties alone can reach thousands of dollars per account per year, and forms like 5471 and 3520 carry $10,000-plus penalties. Streamlined trades that exposure for a clean, penalty-light catch-up. The risk of doing nothing is not just the penalties but losing access to Streamlined entirely if the IRS contacts you first.

What a typical UK case looks like

A common TaxStone Streamlined client is an American who moved to the UK years ago, has a UK salary, a current account, a workplace pension and maybe an ISA, and simply did not know they still had to file. For them the picture is usually: 0% IRS penalty (Foreign procedure), little or no actual US tax (the Foreign Tax Credit covers the UK-taxed salary), and a professional fee for preparing three clean years plus six FBARs and the certification. The ISA may need attention for PFICs, which can add a little. It is a defined, finite cost — not an open-ended liability.

How to get an accurate quote

Confirm you qualify for the Foreign procedure (the non-residency test) — this sets the 0% penalty.
List your foreign accounts, investments, pensions, property and any business interests.
Flag any funds/ISAs (possible PFICs) and any UK company or partnership.
Gather three years of income details and six years of account balances.
Ask for a fixed fee once the adviser has seen this picture.

Get a fixed quote before you commit

The honest answer to 'what does Streamlined cost?' is: usually no IRS penalty if you qualify as foreign, whatever modest tax you genuinely owed, and a professional fee that depends on your asset mix. The way to remove the uncertainty is a proper scoping conversation. At TaxStone we review your situation and quote a fixed Streamlined fee up front, so you know the full cost before any work begins — and for most UK-based Americans, it buys a clean slate with the IRS for good.