How many years does a Streamlined Foreign Offshore Procedures submission cover?

Two different periods apply. The IRS requires delinquent or amended income tax returns for each of the most recent 3 years for which the U.S. tax return due date, or properly applied for extended due date, has passed, and any delinquent FBARs for each of the most recent 6 years for which the FBAR due date has passed. Income tax returns cover three years; FBARs cover six. Both periods are calculated at the date of submission, not chosen by the filer.

Which tax years are in the streamlined window as at 24 August 2026?

For a UK-resident American who did not apply for an extension for 2025, the covered return years are 2023, 2024 and 2025, because the 15 April 2026 and 15 June 2026 due dates have both passed. Where Form 4868 was properly filed for 2025, its due date of 15 October 2026 has not passed, so the covered years are 2022, 2023 and 2024. This position is stated as at 24 August 2026 and changes as due dates pass.

Does filing an extension change which years the streamlined procedures cover?

Yes. The IRS test refers to the most recent three years for which the U.S. tax return due date, or properly applied for extended due date, has passed. A properly filed Form 4868 pushes a US person abroad out to 15 October, so that year is not yet in the covered period and the window steps back by one year. Note that an extension of time to file is not an extension of time to pay: interest still accrues on any tax unpaid from the regular due date.

Are six years of FBARs really required under the streamlined procedures?

Yes. The IRS requires any delinquent FBARs for each of the most recent 6 years for which the FBAR due date has passed. They are filed electronically through the FinCEN BSA E-Filing System, not with the paper tax package, selecting Other as the reason for filing late and explaining that the filing is made under the Streamlined Filing Compliance Procedures. The FBAR itself is due 15 April following the calendar year reported, with an automatic extension to 15 October.

What happens to a year inside the FBAR window but outside the return window?

It contributes an FBAR to the submission but no income tax return, because the streamlined instructions call for returns only for the three covered years. That asymmetry is normal. The pre-window years still have to be worked: the FBAR figures being certified must be accurate, the underlying UK account records should be retained, and the narrative on Form 14653 must explain the failure to submit FBARs across all six years, not only the three return years.

Do Form 5471 and Form 8938 follow the same three-year period?

Yes. Neither form has its own streamlined window. Form 8938, Statement of Specified Foreign Financial Assets, must be attached to the annual income tax return, and Form 5471 is filed by US officers, directors and shareholders of certain foreign corporations in the same way, so both travel with whichever three years the return window covers. The IRS instruction to write Streamlined Foreign Offshore in red at the top of each information return reflects that they form part of the return package.

Streamlined Foreign Offshore Procedures Tax Years Guide

The Streamlined Foreign Offshore Procedures tax years are set by two separate clocks running at different speeds. For income tax, the IRS requires delinquent or amended returns for each of the most recent 3 years for which the U.S. tax return due date, or properly applied for extended due date, has passed. For foreign account reporting, it requires any delinquent FBARs for each of the most recent 6 years for which the FBAR due date has passed. Those are the exact tests published by the IRS on its page for US taxpayers residing outside the United States, and the wording carries more weight than the headline numbers, because each window advances when a due date passes rather than on any single calendar anniversary.

As at 24 August 2026, a US person resident in the United Kingdom who did not apply for an extension of time to file for 2025 is looking at income tax returns for 2023, 2024 and 2025, and at delinquent FBARs reaching back to calendar year 2019. Apply for an extension for 2025 and the return window steps back a year. This page works through how each window is measured, how the two interact, what happens to the years that sit outside them, and how to keep the years actually filed identical to the years certified on Form 14653 when a package is prepared in London and posted to Texas.

What are the Streamlined Foreign Offshore Procedures tax years?

The Streamlined Foreign Offshore Procedures tax years are two defined periods that the IRS refers to as the covered tax return period and the covered FBAR period. The covered tax return period is the most recent three years for which the U.S. tax return due date, or properly applied for extended due date, has passed. The covered FBAR period is the most recent six years for which the FBAR due date has passed. Neither period is chosen by the filer. Both are calculated as at the moment the submission is made, and both are recalculated automatically each time one of the relevant statutory dates goes by.

The mechanics that follow from those two periods are prescriptive. The IRS instructions for taxpayers residing outside the United States call for a complete and accurate return for each of the three years, using Form 1040X where a return for that year was filed previously, together with all required information returns. Every one of those documents has to carry the words Streamlined Foreign Offshore written in red at the top of the first page, and the same instruction applies at the top of each information return. The whole package is sent in paper form to the IRS at 3651 South I-H 35, Stop 6063 AUSC, Attn: Streamlined Foreign Offshore, Austin, TX 78741, because electronic submissions are not accepted.

Three income tax return years: Forms 1040 or 1040X plus every required information return for those same three years.
Six FBAR years: filed electronically through the FinCEN BSA E-Filing System, not with the tax package.
One certification: Form 14653, Certification by U.S. Person Residing Outside of the U.S., covering eligibility and the non-willful character of the failures.
Payment of all tax and interest due for the three return years, submitted with the package.
Red-ink marking on the first page of each return and each information return.
Paper filing only, to the Austin service centre address published by the IRS.

Which three income tax return years are covered as at 24 August 2026?

Take the 2025 tax year first, because it is the one that decides where the window sits. For a calendar-year filer the regular due date of the 2025 return was 15 April 2026. A US citizen or resident alien abroad is allowed an automatic two-month extension, which the IRS describes as producing an automatic extended due date of 15 June. Both of those dates are behind us on 24 August 2026. On either measure, therefore, the due date for the 2025 return has passed, and 2025 sits inside the covered tax return period.

Counting back three years from there produces returns for 2023, 2024 and 2025. That is the default answer for a UK-resident American assembling a package in late August 2026 who has not filed Form 4868 for 2025. The 2022 year, which many filers assume is still in scope because it was in scope for anyone who submitted during 2025, has dropped out. This is the single most common sequencing error in cross-border catch-up work: a file opened eighteen months ago is worked to a year map that has since moved on.

One nuance is worth flagging for high-net-worth filers with complicated returns. The IRS test refers to a properly applied for extended due date. The two-month extension available to those living abroad is automatic rather than applied for, so there is a live question about whether 15 April or 15 June is the operative date for a person in the UK. As at 24 August 2026 the point is academic, because both have passed. It stops being academic in the window between 15 April and 15 June in any year, and a package assembled in that gap needs the position on the year map documented rather than assumed.

How does a filed extension change which years you have to file?

A properly filed Form 4868, Application for Automatic Extension of Time To File U.S. Individual Income Tax Return, pushes the due date for a US person abroad out to 15 October. Where that extension has been filed for 2025, the 2025 due date has not passed as at 24 August 2026, so 2025 is not in the covered tax return period. The three most recent years for which a due date has passed become 2022, 2023 and 2024. The package shifts back one full year, and so does the set of information returns that has to accompany it.

That makes the extension a genuine lever over the composition of a streamlined package rather than an administrative footnote. It also carries a cost the IRS states plainly: even where an extension is allowed, interest is payable on any tax not paid by the regular due date of the return. An extension buys time to file, not time to pay. For a London-based filer with a materially higher US liability in one particular year, the arithmetic of shifting the window against the interest running on unpaid tax is a calculation to be done on the actual numbers, not a rule of thumb.

There is a second effect that is easy to miss. Eligibility for the streamlined foreign offshore route depends on a non-residency requirement that the IRS tests over the most recent three years for which the U.S. tax return due date, or properly applied for extended due date, has passed. For a US citizen or lawful permanent resident, the requirement is that in one or more of those years the individual had no US abode and was physically outside the United States for at least 330 full days. Because that test runs over the same moving three-year window, an extension that shifts the return years also shifts the years across which physical presence is measured. Anyone who relocated from New York to London part-way through the period should model both windows before choosing.

Why are six years of FBARs required, and which six?

The FBAR runs on a different clock because it is not a tax return. It is FinCEN Form 114, filed electronically through the FinCEN BSA E-Filing System, and the IRS is explicit that you do not file the FBAR with your federal tax return. It is due where the aggregate value of foreign financial accounts exceeded 10,000 US dollars at any time during the calendar year reported. The IRS describes it as an annual report due 15 April following the calendar year reported, with an automatic extension to 15 October. Under the streamlined instructions, delinquent FBARs are filed electronically, selecting Other as the reason for filing late and explaining that the filing is being made under the Streamlined Filing Compliance Procedures.

Applying the six-year test as at 24 August 2026 requires a decision about the automatic extension. The FBAR for calendar year 2025 was due 15 April 2026 but carries an automatic extension to 15 October 2026, which has not yet arrived. On the reading that follows the IRS wording literally, the FBAR due date for 2025 has not passed, and the six most recent years for which it has passed are 2019, 2020, 2021, 2022, 2023 and 2024. On the stricter reading that keys off 15 April alone, the six years would be 2020 to 2025.

In preparation terms the practical answer is not to leave the question hanging. Where an FBAR is required for the most recent calendar year and its own deadline has not yet expired, the disciplined approach is to file that year on time in the ordinary way through the BSA E-Filing System and to state clearly on the certification which six years are being remedied as delinquent. That leaves no unexplained gap in the account record, which is the outcome the exercise exists to produce.

The FBAR threshold is aggregate value over 10,000 US dollars at any point in the calendar year, not a year-end balance.
FBARs are filed with FinCEN, never attached to a Form 1040 or posted to the Austin address.
The six-year FBAR window will always extend further back than the three-year return window.
The IRS advises that where it has not contacted you about a late FBAR and you are not under civil or criminal investigation, late FBARs should be filed as soon as possible to keep potential penalties to a minimum.

What happens as the window rolls over at year end, or mid-project?

The most persistent misconception about the Streamlined Foreign Offshore Procedures tax years is that the window turns over on 31 December. It does not. Nothing in the IRS test refers to a calendar year end. Both windows are triggered by due dates, and the due dates that matter are 15 April, 15 June and 15 October for income tax returns, and 15 April and 15 October for FBARs. A package assembled on 20 December 2026 and one assembled on 20 January 2027 sit on exactly the same year map, because no relevant due date falls between them.

The dates that genuinely move the window in the twelve months from now are therefore predictable, which is what makes them manageable. Once 15 October 2026 passes, the 2025 return year is inside the covered period for everyone, including those who extended, and the 2025 FBAR joins the six-year set. Once 15 April 2027, and then 15 June 2027, pass, the 2026 year enters the return window and 2023 leaves it. Anyone whose file is open across one of those dates should treat the map as provisional until the package is actually posted.

This matters more for a UK filer than for a domestic one for a purely logistical reason. The submission must be sent in paper form to Austin, Texas, which means international post from the United Kingdom, with the delivery interval that implies. A package printed, signed and boxed in the first week of October, using a year map built on an unexpired extension, can be in transit when 15 October arrives. Building in a buffer around the pivot dates, rather than posting into them, avoids the problem entirely.

Worked example: mapping a London package year by year

This is an illustrative example only. Assume a US citizen who has lived and worked in London since 2016, employed in banking, holding two UK current accounts, a UK savings account, a UK brokerage account and a 15 per cent shareholding in a UK company she co-founded. She has never filed a US return or an FBAR. Aggregate UK account balances first exceeded 10,000 US dollars during 2018 and have exceeded it every year since. She approaches the exercise on 24 August 2026 and has not filed Form 4868 for 2025.

Her covered tax return period is 2023, 2024 and 2025, because the due dates for all three, on both the 15 April and the 15 June measure, have passed. Three delinquent Forms 1040 are prepared, each marked Streamlined Foreign Offshore in red at the top of the first page. Form 8938 is prepared and attached to each of those three returns, because it is filed with the annual income tax return, and Form 5471 is prepared for the same three years in respect of the UK company, again marked in red. Form 14653 lists precisely those three tax years and nothing else, and payment of the tax and interest computed for those three years accompanies the package.

Her covered FBAR period, on the reading that respects the automatic extension, is 2019 through 2024: six delinquent filings through the BSA E-Filing System, each selecting Other as the reason for late filing with the streamlined explanation. Her 2025 FBAR is not delinquent, so it is filed on time before 15 October 2026 in the ordinary way. Calendar year 2018, when her balances first crossed the threshold, sits outside both windows. So do her 2019 to 2022 income tax return years, even though FBARs for four of them are going in. That asymmetry is the normal shape of a streamlined package, not a defect in it.

How do Form 5471 and Form 8938 follow the return years?

Information returns do not have an independent streamlined window. Form 8938, Statement of Specified Foreign Financial Assets, must be attached to the annual income tax return of the taxpayer, so it travels with whichever three years the return window happens to cover. Form 5471, Information Return of U.S. Persons With Respect To Certain Foreign Corporations, works the same way for the US officers, directors and shareholders of certain foreign corporations who are within its scope. The IRS instruction to write Streamlined Foreign Offshore in red at the top of each information return reflects exactly this: the information returns are part of the return package, filed for the return years.

For a founder or investment professional in the UK, the reporting thresholds are the reason this rarely stays simple. The IRS sets Form 8938 thresholds for taxpayers living abroad at more than 200,000 US dollars at year end or 300,000 at any point in the year for an unmarried filer, and more than 400,000 at year end or 600,000 at any point for a married filing jointly filer. Those are asset-value tests measured within each covered year, so a year in which a UK company holding was revalued, or a liquidity event settled, can carry a filing obligation that the adjacent years do not. Each of the three covered years has to be assessed on its own facts.

It also bears repeating that Form 8938 does not relieve filers of FBAR filing requirements. The IRS states the point directly, and notes that certain foreign financial accounts are reported on both Form 8938 and the FBAR under different definitions and reporting rules. A UK brokerage account can therefore appear on three Forms 8938 and six FBARs in the same package, described according to two different rulebooks, and both descriptions have to be right.

What about a UK year inside the FBAR window but outside the return window?

This is the gap almost no guide addresses, and it is where most UK-resident filers actually live. In the example above, 2019 through 2022 are years for which FBARs go into the submission but no income tax return does. If a UK savings account paid interest in 2021, or a UK holding was disposed of at a gain in 2020, those amounts are visible to the IRS on the FBAR record while the corresponding income never reaches a Form 1040 within the package, because 2020 and 2021 are outside the covered tax return period.

The streamlined instructions do not call for returns for those years, and a package should not invent them. What the exercise does require is that the years are understood rather than ignored. In practice that means three things: computing what the position was for the pre-window years so that the FBAR figures being certified are accurate, keeping the underlying UK records for the account years being reported, and making sure the narrative on Form 14653 explains the failures across the FBAR years and not only across the three return years. The certification asks for the specific reasons for the failure to report all income, pay all tax, and submit all required information returns, including FBARs, and the FBAR limb of that sentence reaches back six years.

There is a UK-specific wrinkle in the underlying data. HMRC operates a tax year running 6 April to 5 April, and GOV.UK confirms that the last UK tax year started on 6 April 2025 and ended on 5 April 2026, with the online Self Assessment return for that year due by 31 January 2027. The FBAR and Form 8938, by contrast, are keyed to the calendar year. UK payroll documents, bank interest certificates and broker statements arrive on the HMRC calendar, so every pre-window FBAR year has to be rebuilt from UK data that does not align to it. For six years of accounts across several institutions, that reconciliation is the bulk of the work.

How do you avoid a mismatch between the years filed and the years certified?

A streamlined submission is internally cross-referenced. Form 14653 identifies the years being remedied, the returns in the box are supposed to be those same years, the information returns attach to those same years, and the payment is computed on those same years. If the window moves between the day the certification is drafted and the day the package is posted from the UK, that internal consistency breaks. The submission then either covers a year the certification does not mention, or omits a year that is now inside the covered period.

The discipline that prevents this is straightforward. Fix the year map in writing at the outset, record the date it was calculated and the extension position it assumed, and re-derive it immediately before signing. Sign the certification and date the return package as close together as the logistics allow, and avoid posting across 15 April, 15 June or 15 October. Where an extension was filed for the most recent year, note on the file which of the two possible windows applies and why, so the reasoning survives a change of preparer.

Write the year map down with a calculation date, and treat it as provisional until posting.
Re-derive the three return years and six FBAR years on the day the certification is signed.
Do not post a package across 15 April, 15 June or 15 October.
Check that the return years, the information return years, the certified years and the payment computation all name the same three years.
File the FBARs and keep the FinCEN acknowledgement references on file alongside the paper package copy.

Should a UK filer deliberately wait for the window to roll?

The question comes up whenever one year in the window is materially worse than the others, and it deserves a straight answer rather than a reflex. Because the covered tax return period is the most recent three years for which a due date has passed, waiting for the next pivot date does push the oldest year out of scope. A UK filer with a large 2023 event and quiet years either side can see, arithmetically, that 2023 leaves the return window once 15 April or 15 June 2027 passes. Filing an extension for the current year has a similar one-year effect available immediately.

Set against that are three considerations that usually dominate. First, the six-year FBAR window rolls too, but far more slowly relative to the accounts being reported, so the account record for the problem year very often stays inside the submission regardless. Second, the streamlined route depends on the filer coming forward before the IRS makes contact, and FATCA reporting by UK financial institutions means the timing of that contact is not within the control of the filer. Third, the non-residency test moves with the return window, so waiting can disturb eligibility itself for anyone whose physical presence in the UK is not uniform across the period. Interest also continues to accrue on unpaid tax from the regular due date throughout any delay.

The defensible version of this analysis is narrow. Where a pivot date is weeks away and the file is not yet complete, aligning the posting date with the new window is ordinary sequencing. Where the proposal is to sit on a known non-compliance for a year in the hope that a bad year ages out, the exposure created by the delay generally exceeds the benefit, and it does nothing about the FBAR years at all.

What about years already filed, and years outside the window?

A covered year for which a return was already filed is not skipped. The IRS instruction is to submit a complete and accurate amended return for that year using Form 1040X, marked in red like every other document in the package, with the omitted foreign income and any missing information returns included. Mixed packages are common: a UK-resident American who filed for one of the three years and not the other two submits one Form 1040X and two delinquent Forms 1040, all three named on the certification.

Years falling outside both windows are simply outside the submission. There is no mechanism within the streamlined foreign offshore procedures for reaching further back, and adding unrequested years does not strengthen a package. Where a late FBAR relates to a year outside the six-year set, it is filed through the FinCEN BSA E-Filing System with a reason given for the late filing, in line with the general IRS position that late FBARs should be filed as soon as possible where the IRS has not made contact and no civil or criminal investigation is in progress.

The reason to get the boundaries right is the protection attached to a properly scoped submission. The IRS states that eligible taxpayers filing the three years of returns and six years of FBARs under these procedures will not be subject to failure-to-file and failure-to-pay penalties, accuracy-related penalties, information return penalties, or FBAR penalties, unless an examination results in a determination that the original tax noncompliance was fraudulent. That protection is defined by reference to the covered years. Getting the year map right is therefore not administrative tidiness; it is what the protection is measured against.

Building the year map before you build the package

Every well-run streamlined preparation starts with the same short sequence, performed before a single return is drafted. It takes an hour and it determines the scope, cost and content of everything that follows.

Confirm today's date and establish which US filing deadlines, 15 April, 15 June and 15 October, have passed for the most recent tax year.
Establish whether Form 4868 was properly filed for that year, and record the answer with evidence.
Derive the three covered return years and the six covered FBAR years from those facts, and note the calculation date.
Test the non-residency requirement across the same three-year window, year by year.
For each of the three return years, assess Form 8938 and, where a foreign company interest exists, Form 5471.
For each of the six FBAR years, list every foreign financial account and its maximum value during that calendar year.
Identify the pre-window years that carry FBARs but no return, and rebuild the underlying UK data for them.
Diarise the next pivot date and check the map again before signing and posting.

The Streamlined Foreign Offshore Procedures tax years are, in the end, arithmetic performed on published due dates. What makes them error-prone is that the arithmetic is done once, early, and then relied on for months while the inputs quietly change. The figures set out here are stated as at 24 August 2026; a package assembled after 15 October 2026, or after 15 April 2027, will sit on a different map. Recalculate at the point of signature, keep the return years and the certified years identical, and the rest of the exercise is documentation.