Is interest in a UK cash ISA taxable on a US return?

Yes. The UK does not usually tax ISA interest, but US domestic law has no matching exemption, and a US citizen or green card holder is taxed on worldwide income. Cash ISA interest is reported as taxable interest on Schedule B of Form 1040 for the calendar year in which it is credited, and the account itself is reported on the FBAR where the aggregate foreign account threshold is exceeded.

Can I use the Streamlined Foreign Offshore Procedures if I already filed US returns?

Yes. The IRS states that the procedures require delinquent or amended returns for each of the most recent three years for which the due date has passed. A taxpayer who filed returns but omitted UK interest files Form 1040-X for each of those three years, marked Streamlined Foreign Offshore in red, together with Form 14653, six years of FBARs and payment of tax and interest.

Is there a 5 percent penalty for UK-resident Americans using the streamlined route?

No. The miscellaneous offshore penalty applies under the separate domestic procedures for US residents. A taxpayer who meets the non-residency requirement and complies with the Streamlined Foreign Offshore Procedures is not subject to failure-to-file, failure-to-pay, accuracy-related, information return or FBAR penalties. The taxpayer pays the tax due for the three years and statutory interest on it.

If HMRC charged no tax on my savings interest, will I owe US tax on it?

Quite possibly. The foreign tax credit only offsets US tax with foreign tax actually paid or accrued. Interest generally falls in the passive category, which has its own limitation on Form 1116, so surplus credits from UK tax on salary cannot be applied to it. Where no UK tax was charged on the interest, the US tax on it is generally payable at the taxpayer's marginal rate.

Can I just file my late FBARs and leave the tax returns alone?

Only if every item of income from the accounts was already reported and taxed on your US returns. An FBAR reports accounts and balances, not income, and corrects no tax return. Where UK interest was left off Schedule B, late FBARs on their own leave the omission in place. The correction is amended returns and FBARs filed together under the streamlined procedures.

My UK annual interest summary covers 6 April to 5 April. Which figure goes on my US return?

Neither summary figure goes on directly. The US return uses the calendar year, so interest must be rebuilt from dated credits on the account statements and assigned to the calendar year in which each amount was credited or became available. The UK tax year summaries are then used as a control total to confirm that no interest has been missed or counted twice.

Streamlined Foreign Offshore: Unreported UK Interest

The Streamlined Foreign Offshore Procedures are the IRS route that a UK-resident American uses to correct US returns that left out UK bank and building society interest, whether the returns were never filed or were filed without the interest. The package is three years of delinquent or amended returns, six years of FBARs, a signed non-willful certification on Form 14653, and full payment of the tax and interest. No penalty is charged under the foreign procedures, but the tax itself is frequently real, because interest the UK did not tax brings no foreign tax credit with it.

This is the fact pattern we see more than any other in the returns we prepare for Americans living in the UK. The salary was reported and covered by credits for UK tax. The savings interest was not, because every UK document the client received said it was tax-free, paid gross, or within an allowance.

Why is UK tax-free savings interest still taxable in the US?

UK tax-free interest is interest that the UK chooses not to charge to income tax; it is not interest that the US has agreed to exempt. A US citizen or green card holder is taxed on worldwide income wherever they live, and the US rules on what counts as taxable interest take no account of UK allowances. IRS Tax Topic 403 at https://www.irs.gov/taxtopics/tc403 states that most interest is taxable income in the year it becomes available to you, and that all interest must be reported even where no information form was issued. A UK bank does not issue a Form 1099-INT, and that absence changes nothing.

On the UK side, GOV.UK explains at https://www.gov.uk/apply-tax-free-interest-on-savings that most people can earn some interest from their savings without paying tax on it, and that interest from Individual Savings Accounts and some National Savings and Investments products is not usually taxed. It also confirms that banks and building societies report the interest they paid to HMRC after 5 April each year, and that HMRC sends a tax calculation only if tax is owed. For a UK-resident American this produces a quiet trap: no UK tax bill, no UK form to complete, and therefore nothing in the household paperwork that prompts a US entry.

The UK sources of interest that we most often find missing from US returns are:

Interest on easy access and notice savings accounts that fell within the UK savings allowances, so no UK tax arose.
Interest inside a cash ISA, which the UK does not usually tax and which has no equivalent exemption in US domestic law.
Interest and similar returns on tax-free government-backed savings products.
Interest on fixed-term bonds and fixed-rate deposits, credited only at maturity and so absent from the client's mental picture of annual income.
The client's half of interest on a joint account with a UK spouse, which HMRC splits equally between the holders by default.
Small amounts of interest on current accounts and on accounts opened years ago and since forgotten.

Two reliefs that clients assume will rescue the position do not. The foreign earned income exclusion applies to earned income such as salary, so it does not shelter interest. And the US-UK income tax treaty contains a saving clause under which the US broadly keeps the right to tax its own citizens, so UK residence does not remove the US charge.

What does Schedule B Part III ask about UK accounts?

Schedule B is the Form 1040 schedule on which interest and ordinary dividends are listed and on which the foreign account questions are answered. The IRS instructions at https://www.irs.gov/instructions/i1040sb say that Schedule B is used if you had over $1,500 of taxable interest or ordinary dividends, and separately that Part III must be completed by anyone who had a financial interest in, or signature authority over, a foreign financial account. A UK-resident American with a UK current account therefore completes Part III every year, even in a year when the interest is trivial.

Part III asks, at line 7a, whether at any time during the year you had a financial interest in or signature authority over a financial account in a foreign country. The instructions say to check Yes even if you are not required to file FinCEN Form 114. The second question on line 7a asks whether you are required to file FinCEN Form 114, and line 7b asks for the country or countries where the accounts are located if you are. The same instructions state the FBAR test: a filing is required where the aggregate value of foreign financial accounts exceeds $10,000 at any time during the year. They also warn that Form 8938 may be required regardless of whether an FBAR is.

This matters for the correction because Part III is where a filed return makes a positive statement. A return that omitted the interest and also answered No on line 7a, or left Schedule B off altogether, contains two errors, and the Form 14653 narrative has to address both.

Who can use the Streamlined Foreign Offshore Procedures?

The IRS page at https://www.irs.gov/individuals/international-taxpayers/u-s-taxpayers-residing-outside-the-united-states sets out the terms for US taxpayers residing outside the United States. A taxpayer must meet the general eligibility criteria for the streamlined procedures, meet the non-residency requirement, have failed to report income from a foreign financial asset and pay tax on it, and may also have failed to file an FBAR. Those failures must have resulted from non-willful conduct. Omitted UK savings interest fits that description exactly: it is income from a foreign financial asset on which US tax was not paid.

The non-residency test for US citizens and green card holders is that, in at least one of the most recent three years for which the US return due date has passed, the individual did not have a US abode and was physically outside the United States for at least 330 full days. For joint filers, both spouses must meet the requirement. A long-term UK resident usually meets this comfortably, but we still count days from travel records for each of the three years, because senior clients with heavy US business travel can fail the test in a year they assumed was safe. Only one qualifying year is needed, but it must be documented.

The general eligibility criteria on the main streamlined page at https://www.irs.gov/individuals/international-taxpayers/streamlined-filing-compliance-procedures add three conditions. The taxpayer must have a valid taxpayer identification number, must not be under IRS civil examination for any year, and must not be under criminal investigation by IRS Criminal Investigation. Once the IRS has opened an examination, the streamlined route is closed, which is the practical reason not to wait once an omission has been identified.

If I filed returns but left the interest off, do I file amended returns?

Yes. The procedures cover both cases. The IRS page states that the submission consists of delinquent or amended returns for each of the most recent three years for which the US tax return due date has passed, together with all required information returns, and delinquent FBARs for each of the most recent six years for which the FBAR due date has passed. Where a return was previously filed, the taxpayer files an amended return on Form 1040-X for each of the three years. Where no return was filed, an original Form 1040 is filed for each year.

A complete submission from a filer who omitted UK interest contains the following:

A Form 1040-X for each of the most recent three years, each with a corrected Schedule B showing the interest and correct Part III answers, and a recomputed foreign tax credit.
Any information returns that should have been filed for those years, such as Form 8938 where the specified foreign financial asset thresholds were met.
Streamlined Foreign Offshore written in red at the top of the first page of each return and each information return, which is how the IRS routes the package.
The original signed Form 14653 certification, with a copy attached to each tax return and information return.
Payment of all tax due on the returns and all applicable statutory interest on the late amounts.
FBARs for each of the most recent six years, filed electronically with FinCEN rather than posted with the returns, selecting Other as the reason for late filing and entering Streamlined Filing Compliance Procedures as the explanation.

The returns are submitted on paper to the dedicated IRS address in Austin, Texas given on the IRS page. The IRS states that receipt will not be acknowledged, so we send every package by a tracked method. The three-year and six-year windows are fixed by reference to due dates that have passed, not chosen by the taxpayer: a client whose omission runs back fifteen years still amends three returns and files six FBARs.

Why is filing the late FBARs alone not enough?

A late FBAR reports the existence and maximum value of an account. It reports no income and corrects no tax return. Many guides still describe a standalone late FBAR fix, and some still name an IRS procedure for it whose page the IRS has since withdrawn. What remains is the mechanism itself: a late FBAR is filed through FinCEN's BSA E-Filing System with a reason for late filing selected. That suits a filer who reported all the income from the accounts and simply did not file the account report.

Where interest was omitted, an FBAR-only filing does not solve the problem. It places on record, year by year, accounts and balances that the filed income tax returns show no income from. In our preparation work the first triage question is therefore not whether FBARs are missing but whether every pound of interest reached Schedule B. If it did not, the correction is a streamlined submission with amended returns, not a set of late FBARs on their own.

How does the Form 14653 certification work when the interest is small but the balances are large?

Form 14653 is the certification by a US person residing outside the United States that they are eligible for the Streamlined Foreign Offshore Procedures, that all required FBARs have now been filed, and that the failures resulted from non-willful conduct. The IRS defines non-willful conduct as conduct that is due to negligence, inadvertence, or mistake, or conduct that is the result of a good faith misunderstanding of the requirements of the law. The form is signed under penalties of perjury and requires a statement of the specific facts explaining the failure.

High-net-worth clients often assume that a small amount of omitted tax makes the certification a formality. It does not. The certification is about the taxpayer's state of mind. A client with seven-figure sterling deposits earning modest interest has a small tax correction and a large reporting failure, and the narrative has to explain the second as carefully as the first.

The failure mode we see most often is a narrative that is true but generic: the client did not know UK interest was taxable in the US. A statement at that level gives the reader nothing to test. The narratives we prepare with clients work through the facts in order: when and why the accounts were opened; the UK tax treatment the client was told about; who prepared the US returns and what that preparer asked about foreign accounts; how Schedule B Part III was answered on each filed return and why; how the error was discovered; and what was done once it was. Unfavourable facts go in, alongside the context that explains them. A banker who signed returns answering No to the foreign account question has a harder narrative than a client whose preparer never raised it.

Where the facts do not support a non-willful certification, the streamlined route is not available and the form should not be signed.

Is there a penalty under the foreign procedures?

No. A taxpayer who is eligible for the Streamlined Foreign Offshore Procedures and complies with all the instructions will not be subject to failure-to-file penalties, failure-to-pay penalties, accuracy-related penalties, information return penalties or FBAR penalties. There is no miscellaneous offshore penalty under the foreign procedures. The percentage-based offshore penalty that readers see quoted belongs to the separate domestic procedures for US residents and is not part of this route.

What is charged is the tax and the statutory interest on it, paid with the submission. Three limits on the protection are worth stating plainly. Penalties already assessed for the years concerned are not abated. If a submitted return is later examined and the IRS determines an additional deficiency beyond what was reported, penalties can apply to that additional amount. And the IRS says streamlined returns are not audited automatically but may be selected under its normal processes and checked against information received from banks and other sources.

Will US tax actually be due after the foreign tax credit?

Often it will, and this is the point most guides skip. The foreign tax credit is a credit for foreign income tax paid or accrued. Where the UK charged no tax on the interest, there is no UK tax on that income to credit. The IRS instructions for Form 1116 at https://www.irs.gov/instructions/i1116 explain that the credit is computed separately for each category of income, on a separate Form 1116, and that passive category income generally includes interest. Salary falls into a different category.

The consequence for a well-paid UK resident is counter-intuitive. UK income tax on employment income often exceeds the US tax on the same income, leaving surplus credits. Clients assume that surplus will absorb the US tax on interest. It cannot, because the surplus sits in the category that holds the salary and the interest sits in the passive category with its own limitation. A passive category with interest income and little or no UK tax attached produces little or no credit, and the US tax on that interest is payable in full at the taxpayer's marginal rate.

The position is different where the UK did tax some of the interest, for example where a client's non-ISA interest exceeded the UK allowances and tax was collected through self assessment or a tax code adjustment. That UK tax is creditable, and it has to be traced to the interest it relates to and to the correct US year. The Form 1116 instructions also contain a high-taxed income rule that can move heavily taxed passive income out of the passive category, which needs checking when UK rates on the interest were high.

Worked illustration: UK-tax-free interest omitted from three filed returns

The following is an illustration only, with invented figures and assumed rates, not a statement of any client's position or of current tax rates. A US citizen has lived in London for twelve years, is employed in investment banking, and has filed a US return every year, claiming foreign tax credits on salary. She holds cash ISAs built up over many years and a tax-free government-backed savings product, with combined balances of about 200,000 pounds, plus a current account. The savings produce interest of 8,000 pounds a year, none of it taxed in the UK. None of it appeared on her US returns, Schedule B was not attached, and no FBARs were filed.

Assume an exchange rate of 1.25 dollars to the pound for every year, purely for simplicity, and an assumed US marginal rate of 24 percent. The omitted interest is 10,000 dollars a year. The UK tax on it is nil, so the passive category credit is nil, and her surplus credits from UK tax on salary cannot be used against it. The additional US tax is 2,400 dollars for each of the three amended years, 7,200 dollars in total, plus statutory interest on each year's amount.

Her submission is three Forms 1040-X with Schedule B and corrected Part III answers, Form 8938 for any year in which the thresholds were met, six FBARs listing every UK account including the current account, Form 14653 with a specific narrative, and payment. No penalty is charged.

How is UK interest converted into dollars?

US returns are prepared in dollars. The IRS guidance at https://www.irs.gov/individuals/international-taxpayers/foreign-currency-and-currency-exchange-rates says that a taxpayer whose functional currency is the dollar must translate items of income into dollars using the exchange rate prevailing when the item is received, paid or accrued, and that where there is more than one exchange rate the one that most properly reflects income should be used. The IRS does not publish a single official rate; the page points to governmental and commercial sources and links to a table of yearly average rates.

For interest credited monthly through the year, a yearly average rate applied to the calendar-year total is the method we normally adopt, applied consistently across all three amended years and across all accounts. For a single large credit, such as maturity interest on a fixed-term bond, the rate for the date of the credit reflects the income more accurately than an annual average. FBAR balances are converted under FinCEN's own instructions, so the rate on the FBAR and the rate on Schedule B for the same account can legitimately differ. Payment of the tax itself must be remitted in US dollars.

When is interest on a fixed-term product taxable?

Fixed-term bonds and fixed-rate deposits are where timing errors appear even in files that are otherwise careful. IRS Publication 550 at https://www.irs.gov/publications/p550 treats these products under its rules for certificates of deposit and deferred interest accounts. Where an account matures in one year or less and pays interest in a single payment at maturity, the interest is generally reported when it is actually received or can be collected without a substantial penalty. Where the term is more than one year and interest is deferred, the original issue discount rules apply, and a part of the total interest must be included in income each year even though nothing has been paid.

A UK institution issues no Form 1099-OID, so the annual accrual on a two, three or five year bond has to be computed from the product terms. For a streamlined submission this means a bond that has not yet matured may already have accrued reportable interest inside the three-year window, and any UK tax paid on a maturity payment has to be matched carefully to the US income it relates to.

How do you rebuild the interest figures from annual interest summaries?

UK banks and building societies produce annual interest summaries, and they are the natural starting point, but they are built for the UK tax year, which runs from 6 April to 5 April. The US return of an individual uses the calendar year. An annual interest summary therefore straddles two US years and cannot be copied onto Schedule B.

The method we use is to treat the annual summaries as a control total and the statements as the source. For each account we extract every interest credit by date from the statements, assign it to the calendar year in which it was credited or became available, and then reconcile the dated credits back to the UK tax year summaries. Fixed-term products need the accrual treatment described above. Joint accounts need a decision, supported by evidence of who funded the account, on how the interest is divided for US purposes.

The schedule has to reach back six years for the account list and maximum balances on the FBARs, and three years for income. Closed accounts are the usual obstacle; where a record genuinely cannot be obtained, we document the request and use the best available evidence. One schedule then feeds Schedule B, Form 1116, Form 8938 and the FBARs, which is what keeps the four filings consistent with each other.

What should a UK-resident American do next?

The order of work matters. Do not file isolated late FBARs or a single amended year before the whole position is mapped. Confirm the non-residency test with a day count. Gather six years of statements for every account, open or closed. Have the interest schedule, the amended returns, the FBARs and the Form 14653 narrative prepared together as one file, so that every figure and every fact agrees. Then submit the complete package with payment, and bring the current year's return and FBAR into line so the correction is not followed by a new omission. We prepare streamlined submissions of this kind for UK-resident Americans as a tax preparation and compliance service.