A late Form 3520 follows the state of your income tax returns. If those returns were filed and complete, the form normally goes in alone under the IRS delinquent information return procedures, with a reasonable cause statement. If returns are missing or income was left off, the form usually belongs inside a Streamlined package, where the penalty position differs by route.
This post is for US citizens and green card holders in the UK who took money from British parents and found out about the form afterwards. Our post on inheriting from UK parents explains what the form is; this one deals only with being late, and extends our guide for people behind on US filings in the UK.
Which route fits a late Form 3520
The test is what else is wrong. A missing form with nothing else outstanding points to the delinquent procedures. Unfiled returns or omitted income point to Streamlined, provided your conduct was non-wilful. An IRS examination or contact changes the answer, so check for those first and read the table below in order.
The delinquent procedures (opens the official IRS page in a new tab) are open to someone who is not under civil examination or criminal investigation and has not been contacted by the IRS about the forms. The page warns that penalties may still be assessed. The Streamlined procedures (opens the official IRS page in a new tab) close once a civil examination opens for any year, whether or not it concerns foreign assets.
Be careful with the income test. The IRS page for taxpayers residing outside the United States (opens the official IRS page in a new tab) describes people who failed to report income from a foreign financial asset and pay the tax due. It does not address someone whose only failure is a form on a gift that is not income. Its protection from information return penalties therefore cannot be assumed on those facts, and a person in that position should expect the delinquent route. The Foreign route also needs 330 full days outside the US in at least one of the last three years.
- IRS examination open, or a letter about these forms: take advice before filing anything
- Returns filed, all income reported, form missing: delinquent procedures with a reasonable cause statement
- Returns unfiled, or interest on the money left off: Streamlined Foreign, if non-wilful and the residence test is met
- Returns filed, income omitted, residence test failed: Streamlined Domestic, with its 5% offshore penalty
- No return required, because income sat below the filing threshold ($5 if married filing separately): delinquent procedures
- Conduct that was wilful: neither route; the voluntary disclosure practice is the place to take advice
Which years are actually late once the gifts are added up
Only years in which your total crossed $100,000 on the US calendar year. The test is applied year by year, so a run of smaller transfers may produce one late form or none. A year below the line has no form to file.
Build the ledger from bank statements before writing anything. British records work against you here, because UK statements, gift letters and accountants often think in tax years running from 6 April to 5 April. The IRS gift page (opens the official IRS page in a new tab) speaks of the tax year, which for most individuals is the calendar year, so a parent's giving has to be re-cut by the date you received it.
Each entry needs a date, a donor, a description and a dollar value. The IRS page on foreign currency (opens the official IRS page in a new tab) says amounts on a US return are expressed in dollars and does not name one official rate. It refers to the rate prevailing at receipt and lists places to find one. Pick a source, note it, and apply it throughout.
How should gifts from British parents be added up
Together, where you know or have reason to know the donors are related. The Form 3520 instructions (opens the official IRS page in a new tab) add gifts and bequests from related nonresident aliens and foreign estates for the threshold, so a mother, a father and a late grandparent's estate can fall into one total. Parents are not tested one at a time.
Timing inside the year does not matter, and neither does the label on the transfer. A birthday transfer, a share of a house sale and an estate distribution all count once received, and each one above a much smaller amount set in the instructions is listed individually. Payments that the IRS treats as qualified tuition or medical payments are left out, which may matter if a grandparent paid fees directly. Whether a given UK school payment qualifies depends on how it was made.
Other sources have their own rules. A payment from a parent's company falls under a separate, lower threshold and may be recharacterised, and a payment from a trust goes in Part III with a penalty of the greater of $10,000 or 35% of the gross reportable amount. The instructions also ask whether a donor acted as a nominee or intermediary for someone else, so money routed through a relative must be traced to its true source. Our page on Form 3520 sets out the parts.
- Both parents, and any estate of a relative, added together
- Parent's company payments tested separately, at the lower threshold
- Will trust or other trust payments moved to Part III
- Qualified tuition or medical payments removed, where the conditions are met
How might this look for an engineer in Leeds
A US citizen employed in Leeds files every US return on time and learns about the form in September 2026. Her records show three transfers: one from her father in March 2023, one from her mother in November 2023, and one from her father in May 2024.
Measured against the threshold, the three transfers were about two thirds, about one half and about two thirds. On UK tax years they fall in 2022/23, 2023/24 and 2024/25, and no year looks reportable, which is how a form like this gets missed. On calendar years the picture changes. Her 2023 receipts come to about seven sixths of $100,000, so a form was due by 15 June 2024 unless she extended. Her 2024 receipts stay below the line, so no form exists for that year.
One form is therefore late, by more than two years. The penalty is 5% of the gift for each month it goes unreported, capped at 25%, so the cap was passed after five months, and it is measured on the reportable gifts rather than only the excess over the threshold. Her interest was on her Form 1040, so she uses the delinquent procedures.
Now change one fact. Suppose the 2023 money sat in a UK savings account and the interest never reached her return. She then has omitted income from a foreign financial asset, so the Streamlined Foreign route opens if her conduct was non-wilful: amended returns for three years, FBARs for six years, the Form 3520 inside the package, and a signed certification. Our IRS streamlined filing service prepares that package, and the FBAR goes to FinCEN separately.
What should a reasonable cause statement rest on
On dated facts showing ordinary care, and on what you did once you knew. The penalty falls away only where the failure was due to reasonable cause and not wilful neglect. A statement that says only that you had never heard of the form is weak on its own, so the surrounding facts have to carry it.
IRS material is unhelpful on bare ignorance. The reasonable cause page (opens the official IRS page in a new tab) says you are responsible for knowing or getting advice on filing, and the international penalties manual (opens the official IRS page in a new tab) says that it is not reasonable to have no knowledge of, or rely solely on others for, the treatment of international transactions. The manual is guidance for IRS staff, last revised in 2021.
Advice is the strongest ground where it exists, but it has limits. For accuracy penalties, the IRS page asks whether an adviser was competent and given all the information, and the manual says relying on someone else to file is not enough by itself. So show what you told your preparer about the money, in the form of an email or an organiser. Repeated failures also count against you, because the manual says they do not support a claim of ordinary care for older years.
- When each transfer arrived, and from whom, matching the form
- Why you treated it as family money, and what you asked at the time
- Who prepared your returns, and what you gave them about the gifts
- The date you learned of the form, and how you learned
- How quickly you then filed, and which other filings you corrected
- A declaration under penalties of perjury, signed by you
How is the form actually sent on each route
Separately under the delinquent procedures, and inside the package under Streamlined. Sending it the wrong way can cost you the terms you were relying on, because each route has its own processing instructions. Keep proof of posting either way.
Under the delinquent procedures, the form is filed under its own instructions rather than attached to an amended return. That means the Ogden service centre, a complete form for each late year, and the words 'Reasonable Cause Statement attached' written on top of the first page. The IRS says statements on Forms 3520 and 3520-A are considered before a penalty is assessed. If a penalty is still charged, our IRS representation work deals with the reply, as the manual calls for a determination letter when reasonable cause is denied.
Under Streamlined, the IRS says required information returns go with the package even where they would normally be filed separately. On the Foreign route, a compliant filer is not subject to information return penalties, unless the original noncompliance proves fraudulent or an FBAR violation wilful. Penalties assessed earlier for those years are not abated, and additional tax found on examination can attract its own. The Domestic route (opens the official IRS page in a new tab) offers the same shelter in exchange for its offshore penalty. Our post on the Form 14653 certification explains the written account.
What about gifts older than the Streamlined period
The IRS pages we read do not settle this. Streamlined covers three years of returns and six years of FBARs, and the penalty wording speaks of those years. A transfer received before that window has no stated home, so the position depends on the facts and should be decided before anything is posted.
The practical question is whether the older form should be filed at all and, if so, how the statement for it sits beside your certification. A non-wilful account that says you only learned in 2026 cannot sit next to a statement implying you knew earlier. Those older years may also have return questions of their own, such as unreported interest, which our individual tax returns work can check first.
Start with the ledger, then the route, then the writing. Our guide to catching up from the UK sets out the other routes, and our gift tax returns service handles the form itself. You can also contact US UK Tax Returns with your dates and transfers before anything is sent.
General information, not advice. The right answer depends on your circumstances and the tax year concerned.
