Streamlined covers the most recent three years for which the US tax return due date, or a properly applied-for extended due date, has passed, and the most recent six years for which the FBAR due date has passed. The IRS uses the same wording for the Streamlined Foreign Offshore Procedures (opens the official IRS page in a new tab) and the Streamlined Domestic Offshore Procedures (opens the official IRS page in a new tab). Those dates decide which calendar years fall inside each window, so the month in which you post the package matters.
This post is for US citizens and green card holders in the UK who are about to prepare a catch-up and want to pin down the years before any work starts. It goes further than our guide for people behind on US taxes in the UK on one question: which returns and which FBARs belong in the package. It covers the return window, the effect of extensions, the FBAR window, the years that count for the non-residency test, a worked example for a package started in late October 2026, and what happens to the years before the window.
Which tax years does a Streamlined submission cover
The most recent three years whose return due date has passed, counted back from when you file. The IRS wording is the most recent three years for which the US tax return due date, or properly applied-for extended due date, has passed. A year whose due date is still ahead is not yet in the window.
On the Foreign route, each of those years needs a complete late or amended Form 1040, with every required information return attached, such as Forms 3520, 5471 and 8938. The IRS instructions say each return and information return is marked Streamlined Foreign Offshore in red at the top of the first page, and the package goes on paper to the address given on the Streamlined Foreign Offshore Procedures (opens the official IRS page in a new tab) page. Tax and interest for every year in the window are paid with it.
The window moves. Because it is measured from due dates, a package sent in spring and one sent in late autumn of the same calendar year can cover different years. The years are therefore fixed by the date the submission is actually posted, not the date the work begins, and a package that slips by a few months may need a further year added. Our IRS streamlined filing service checks the window again before anything is signed.
- A late or amended Form 1040 for each year in the return window
- Every information return those years require, attached to its own return
- A signed Form 14653 certification on the Foreign route
- Payment of all tax and statutory interest for the window
- FBARs for a separate, longer window, filed with FinCEN
How do extensions change which return years are included
They can move the latest year in or out. The window turns on whether the due date, or a properly applied-for extended due date, has passed. For a calendar-year filer the regular due date is 15 April. A properly obtained extension pushes that year's date later, and the year joins the window only once the later date has passed.
A US citizen living outside the US and Puerto Rico on the regular due date gets an automatic two-month extension (opens the official IRS page in a new tab) to 15 June, with a statement attached to the return explaining why they qualify. Interest still runs from 15 April. Publication 54 (opens the official IRS page in a new tab) explains that Form 4868 gives an extension to 15 October in total, and that a taxpayer out of the country can ask by letter for a discretionary further extension to 15 December, sent by the extended due date.
The IRS pages do not say in terms how the automatic two-month extension, which is not applied for, fits the phrase properly applied-for. For a package posted between 15 April and 15 June, the position of the latest year is therefore a point to settle before the returns are prepared. Outside that stretch the answer is usually plain. After 15 October, the latest year is in the window unless a further extension was granted and its date has not yet arrived.
Which six years of FBARs go in the package
The most recent six years for which the FBAR due date has passed. The FBAR has its own calendar: the FBAR (opens the official IRS page in a new tab) is due on 15 April, extended automatically to 15 October, and the IRS says no request is needed for that extension. By late October, the latest calendar year is already inside the FBAR window.
The FBAR window reaches further back than the return window. Each FBAR is FinCEN Form 114, filed electronically through FinCEN's BSA E-Filing System, not with the tax return and not inside the paper package. Within the window, a report is needed for each year in which the combined value of your foreign accounts exceeded $10,000 at any time, counting accounts you could sign on as well as those you owned. Our FBAR filing work prepares each year from the account records.
The two windows are measured separately, so they do not always end in the same year. In late October both normally include the most recent calendar year, which keeps the package straightforward. At other times of year, check each window on its own terms before anything is prepared. Our post on missing the October FBAR extension covers someone whose latest report has only just gone late.
Which years count for the non-residency test
The same three years. A US citizen or green card holder meets the Foreign route's non-residency test if, in any one or more of the most recent three years for which the return due date, or properly applied-for extended due date, has passed, they had no US abode and were physically outside the United States for at least 330 full days.
The test years and the return years are the same set, and one qualifying year is enough. Someone who moved to the UK partway through the window can qualify if a later year meets the 330 full days count. The IRS says that neither temporary presence in the US nor keeping a dwelling there necessarily means a US abode, and points to the abode rules in Publication 54 (opens the official IRS page in a new tab). For a joint return, both spouses must meet the test.
Someone who fails the test in every year of the window is pointed to the Domestic route, which requires that returns were already filed for each of those years and charges a miscellaneous offshore penalty of 5%. The Streamlined Domestic Offshore Procedures (opens the official IRS page in a new tab) measure it on the highest year-end total of the relevant foreign assets across both the return window and the FBAR window, as our post on the Streamlined Domestic penalty base explains. Only the Foreign route carries no such penalty.
How might this look for someone starting in late October 2026
A package posted in late October 2026 will usually cover the 2023, 2024 and 2025 returns and the FBARs for 2020 to 2025. The 2025 return was due on 15 April 2026, and every extension date except the discretionary December one has passed. The 2025 FBAR is past its October date too.
Take a US citizen employed in Manchester who moved from Boston some years ago and has not filed a US return since. She holds a UK current account, a cash ISA and a workplace pension, and started gathering papers this week. Apart from short family visits, she has spent each of the last three years in the UK, comfortably above 330 full days outside the US, and her failure to file came from not knowing the rules still applied to her.
Her package has three late returns, each with the information returns her accounts require, FBARs for each of the six years listing every UK account she held, and a Form 14653 explaining her conduct, as our post on writing the non-wilful certification describes. Had she properly extended her 2025 return to 15 December, that date would still be ahead, and on the IRS wording her return window would be 2022 to 2024 until it passed.
- Return years for a late October 2026 package: 2023, 2024 and 2025
- FBAR years for the same package: 2020 to 2025
- Non-residency test years: the same three return years
- Years before 2023 for returns: outside the package, but not erased
- A package that slips past the next due date: recheck both windows
What happens to the years before the Streamlined window
The procedure does not ask for them. The IRS instructions list returns for the return window and FBARs for the FBAR window, and nothing earlier. That defines what goes into the submission. It does not close the earlier years, and the IRS keeps its usual powers over them.
Some situations make earlier years worth a closer look. A year in which a Form 5471 was required and never filed can stay open, as our post on Form 5471 under Streamlined explains. Someone planning to give up citizenship must certify five years of compliance on Form 8854, so a renunciation plan can mean preparing more than three years of returns, as our post on renouncing from the UK step by step sets out.
Filing extra years is a judgement on the facts, not a requirement of the procedure, and it does not change the window itself. A sensible approach is to fix the years in writing at the start, recheck them just before posting, and keep the records for earlier years in case questions follow. Our individual tax returns work keeps later years on time, and our guide to IRS streamlined filing from the UK sets out the full sequence. You can contact US UK Tax Returns to have your years confirmed.
General information, not advice. The right answer depends on your circumstances and the tax year concerned.
