The automatic extension to 15 June moves two things for a qualifying filer: the date for Form 1040 and the date from which the late-payment penalty runs. Forms attached to the return move with it. Interest does not move, and neither does the FBAR. Form 3520 has its own version of the rule, the gift tax return is unclear, and state returns sit outside it altogether.
This post is for US citizens and green card holders in Britain who want to know exactly what they can leave until June, and for couples where only one spouse has moved. It extends the deadlines section of our guide to US and UK tax returns for Americans in the UK with an item-by-item list, the test on the due date, and a worked example of one spouse abroad.
What does the automatic June extension move
It moves the filing date of the federal income tax return and the date to pay the tax, with interest charged in the meantime. Anything filed as part of that return generally follows it. Each item below has been checked against its own IRS instructions, because the answers differ more than the headline rule suggests.
Publication 54 (opens the official IRS page in a new tab) describes the extension as covering both filing the return and paying federal income tax. That is wider than many summaries suggest, and the practical difference appears in the penalty line. A balance paid in May is still late for interest purposes and on time for the late-payment penalty, provided the filer qualifies. The list is our own arrangement of the IRS rules, set out as moved, not moved, or unclear.
- Moved: the Form 1040 filing date, from 15 April to 15 June
- Moved: the start of the late-payment penalty, which runs from 15 June for a qualifying filer
- Moved with the return: Form 8938 (opens the official IRS page in a new tab), Form 8621 (opens the official IRS page in a new tab) and Form 5471 (opens the official IRS page in a new tab), each due with the return including extensions
- Moved by its own rule: Form 3520, with a separate statement attached to that form
- Not moved: interest, which runs from 15 April, and the FBAR, due 15 April, extended automatically to 15 October
- Not moved: Form 3520-A from the trust, and state returns. Unclear: the Form 709 filing date
Who actually qualifies on the regular due date
A US citizen or resident alien qualifies if, on 15 April, they live outside the US and Puerto Rico and their main place of business or post of duty is also outside, or they are on military or naval duty abroad. The test looks at that single day, and both limbs of the civilian route must be met.
The day-specific test produces results people do not expect. Someone who lands at Heathrow in the last week of April to start a job missed the test, so the return stayed due on 15 April, and they needed Form 4868 filed by then to gain time. Someone who lived and worked in Manchester on the due date and moved back to Chicago in May still qualified. The Form 4868 instructions (opens the official IRS page in a new tab) add that a person who otherwise qualifies keeps the extension even if physically in the US on the date, so a holiday in Florida over the due date does not cost it.
The harder cases sit in the second limb. A retired American in Bath lives abroad but may have no place of business at all, and a British resident working remotely for an American employer may have a contract that points to a US office. The IRS pages we reviewed do not address either situation, so the answer depends on the facts. A person in doubt can remove the question by filing Form 4868 by 15 April, which is open to filers generally.
Does the June extension stop interest and penalties on unpaid tax
It delays one and leaves the other. Interest runs from 15 April on anything unpaid, whatever the reason. The late-payment penalty is assessed from 15 June for a qualifying filer. So a balance settled before the June date carries interest for the gap and, on the IRS wording, no late-payment penalty.
The source of that distinction is a short passage in Publication 54 (opens the official IRS page in a new tab): penalties for paying late are generally assessed from the original due date, unless the taxpayer qualifies for the two-month extension. A filer who expects a balance can estimate it and pay by the regular date, which removes both the interest and any question over the failure-to-pay penalty (opens the official IRS page in a new tab), a monthly charge on the unpaid amount. The Form 4868 instructions are blunt that a good reason for paying late does not remove interest.
Filing and paying then come apart if the return goes beyond June. Form 4868 buys four more months to file, and it does not extend the time to pay. A balance left unpaid after 15 June therefore starts to attract the penalty, even though the return itself is on time. Many Americans in the UK owe little after credits, but that is a result to confirm before relying on it. Estimated instalments are a separate subject, and our post on estimated tax payments for Americans in the UK deals with them.
Which filings keep their own date regardless
The FBAR, Form 3520-A, gift tax payments and state returns all sit outside the federal extension. Each runs on its own rule, and two of them can catch out someone who assumes June applies to everything. Form 3520 is a separate case again, because it gets a June date through its own instructions.
The FBAR goes to FinCEN and is due 15 April, extended automatically to 15 October, with no request needed (opens the official IRS page in a new tab) for the later date. It therefore has more time than the return, and the two dates should not be run together. Form 3520 (opens the official IRS page in a new tab) reaches 15 June on similar conditions, but its instructions ask for a statement included with Form 3520 itself. The statement on the Form 1040 does not obviously serve, because the two are filed separately. Form 3520-A, from a foreign trust, falls due on the fifteenth day of the third month after the trust's year ends, unless a substitute is attached to the owner's Form 3520.
State returns are a matter for each state. The IRS pages describe federal income tax only and do not mention them. Do not assume the federal date carries over: check the state return position with that state's tax agency if you still have a filing there. Our post on leaving California or New York for London explains why a former state can remain relevant, and multi-state filing covers more than one.
Does the June extension cover the gift tax return
The official wording does not settle it. The Form 709 instructions (opens the official IRS page in a new tab) say any extension granted for the income tax return also extends the gift tax return, then name Form 4868 and Form 2350 as the ways of doing that. They do not mention the automatic two-month extension. Payment is clearer: extending the filing date does not move it.
A donor with a reportable gift has a straightforward way past the uncertainty. The instructions provide Form 8892 for someone not requesting an income tax extension, giving six months for the gift tax return, and also a payment voucher for any balance. Filing Form 4868 for the income tax return by 15 April reaches the same result. Our Form 709 page and gift tax returns service cover what the return reports.
How does the extension work when only one spouse is abroad
On a joint return, either spouse qualifying is enough. On separate returns, only the spouse who qualifies gets the extension. That makes filing status something to settle before the regular due date, because a decision taken later can leave the spouse still in the US with a return that was already late.
Take a US citizen employed in Leeds whose US citizen husband stayed in Boston to finish a contract and joined her on 20 May. On 15 April she met the test and he did not. If they file jointly by 15 June, the return is on time, with a statement explaining that she qualified. Interest runs from the regular date on any balance. His move in May plays no part in the analysis, in either direction.
Now suppose they review the figures on 2 June and prefer separate returns. Her return can still go in by 15 June. On the published wording his was due on 15 April, so it is about seven weeks late, and any balance has been exposed to the penalties from that date. Had he filed Form 4868 by the regular date, he would have kept the choice open. Our post on filing status for Americans married to a non-US spouse sets out how the status itself is chosen.
Form 3520 adds a further wrinkle. Suppose the husband inherited from a British aunt above the $100,000 reporting level. The Form 3520 instructions describe the individual who satisfies the conditions and do not repeat the either-spouse rule for joint returns, so his own form may not reach June on his wife's qualification. The guidance is silent on the point, and a Form 4868 filed by him on time would avoid it, since an income tax extension takes Form 3520 to 15 October.
What should you check before relying on the June date
Run through the checks below by the end of March, while Form 4868 and Form 8892 are still available as alternatives. The order is our own construction from the IRS rules. It assumes a calendar-year filer and works from the qualification test outwards to the filings that sit beside the return.
The statement itself is short. The IRS requires one that explains which situation qualified you, and the pages we reviewed prescribe no set wording. A sensible version names the filer, says they lived in Britain on the regular due date, and gives the location of their main place of work. Our individual tax returns service covers the return itself, and our guide for Americans in the UK places this date within the full annual cycle.
- Confirm where you lived and where your main place of work was on 15 April
- For a couple, settle joint or separate before that date, or extend the spouse who does not qualify
- Estimate any balance and pay it by 15 April if you want to avoid interest
- List any Form 3520, Form 709 or state return, and diarise each one separately
- Attach the qualifying statement to the Form 1040, with a further one on any Form 3520
- File Form 4868 by 15 June if the return will not be ready, ticking the out-of-country box
General information, not advice. The right answer depends on your circumstances and the tax year concerned.
