Cook Islands Trust Compliance Requirements

U.S. persons who establish Cook Islands trusts must comply with annual reporting obligations imposed by the Internal Revenue Service and the Financial Crimes Enforcement Network. These obligations exist because Cook Islands trusts are classified as foreign trusts for U.S. tax purposes, and U.S. law requires extensive disclosure of foreign trust arrangements, foreign financial accounts, and foreign financial assets. The reporting requirements apply every year the trust exists, regardless of whether the trust produces income, makes distributions, or changes in any way.

Cook Islands trusts provide asset protection, not tax reduction. The grantor of a Cook Islands trust pays U.S. income tax on all trust income exactly as if the trust did not exist, because the trust is treated as a foreign grantor trust under IRC sections 671 through 679. The compliance burden is the cost of maintaining transparency with U.S. tax authorities while holding assets in a foreign structure that does not recognize U.S. court judgments.

The penalties for noncompliance are among the harshest in federal law. A single missed form can produce a penalty of $10,000 or more. Multiple forms apply to Cook Islands trusts each year, and each form has its own filing system, deadline, and penalty structure. Understanding what must be filed, when, and through which system is essential for anyone who has or is considering a Cook Islands trust.

The Four Compliance Categories

Cook Islands trust grantors face four categories of federal reporting. Each category operates independently, uses different forms, follows different deadlines, and is administered by different agencies or divisions. Filing one category correctly does not satisfy or excuse the others.

Foreign trust information returns (Forms 3520 and 3520-A) require the grantor to disclose the trust’s creation, all transfers to the trust, the grantor’s ownership interest under the grantor trust rules, distributions received, and the trust’s income, assets, and liabilities. These forms are filed on paper with the IRS and carry penalties starting at $10,000 per form per year, scaling up to 35 percent of unreported transfers or distributions. Detailed guidance on these forms, including deadlines, the substitute Form 3520-A mechanism, and the 2024 policy change ending automatic penalties, is available in the Forms 3520 and 3520-A article.

Foreign bank account reporting (FBAR) requires the grantor to file FinCEN Form 114 electronically through the BSA E-Filing System whenever the aggregate maximum value of foreign financial accounts exceeds $10,000 during the calendar year. FBAR is not filed with the IRS and is not attached to any tax return. It is a separate filing with a separate agency (FinCEN), and it is the single most commonly overlooked obligation in Cook Islands trust compliance. Willful FBAR violations carry penalties up to 50 percent of the account balance. Detailed guidance is available in the FBAR requirements article.

FATCA reporting (Form 8938) requires the grantor to disclose specified foreign financial assets on Form 8938, which is filed with the income tax return. The reporting thresholds are higher than FBAR ($50,000 on the last day of the tax year or $75,000 at any time during the year for single domestic filers), and the form covers a broader category of assets including interests in foreign entities. The most consequential penalty for missing Form 8938 is that the statute of limitations on the entire income tax return never begins running, leaving the return open to IRS audit indefinitely. Form 8938 reporting is covered in the IRS tax reporting requirements article.

Income tax reporting and gift tax considerations require the grantor to report all trust income on their personal Form 1040 (because the trust is a grantor trust) and to evaluate whether transfers to the trust constitute completed gifts subject to federal gift tax. The grantor must also answer the foreign trust questions on Schedule B, Part III of Form 1040. These obligations are covered in the IRS tax reporting requirements article.

Why Compliance Failures Happen

The most common compliance failures do not result from intentional evasion. They result from the unusual structure of the reporting obligations themselves.

FBAR uses a different filing system (BSA E-Filing) and a different agency (FinCEN) than every other tax-related form. CPAs who prepare Forms 3520, 3520-A, and 8938 as part of the income tax return may not handle FBAR filing at all. Grantors who assume their CPA covers everything may discover years later that FBAR was never filed. The solution is an explicit annual confirmation between the grantor and the CPA that FBAR has been submitted through the BSA E-Filing System. This problem is discussed further in the FBAR requirements article.

Form 3520-A has an earlier deadline (March 15) than the income tax return (April 15). CPAs accustomed to the April 15 cycle may not realize that a separate extension (Form 7004, using the trust’s EIN) must be filed specifically for Form 3520-A. An income tax extension does not extend the Form 3520-A deadline. The safest practice is to file Form 7004 routinely every year. This issue is explained in the Forms 3520 and 3520-A article.

Forms 3520 and 3520-A are filed on paper by mail to the IRS Service Center in Ogden, Utah. They cannot be e-filed. FBAR, by contrast, must be filed electronically and cannot be filed on paper. The mismatch in filing methods increases the risk that one or the other falls through the cracks.

Form 8938 and FBAR overlap substantially in what they cover but are filed through different systems with different thresholds and different penalties. Both must be filed when both thresholds are exceeded, and filing one does not satisfy the other.

Coordination Among Grantor, Trustee, and CPA

Cook Islands trust compliance requires three parties to work together: the U.S. grantor, the Cook Islands trustee, and the U.S. tax professional (typically a CPA).

The Cook Islands trustee provides the financial information needed to prepare the forms. This includes year-end account statements from all bank and brokerage accounts held by the trust, income summaries broken down by type (interest, dividends, capital gains), expense summaries (trustee fees, bank fees, legal fees), records of any distributions made during the year, and a schedule of assets at year-end with fair market values. The trustee also signs Form 3520-A, because the form is technically the trust’s return.

Cook Islands trust companies are accustomed to U.S. compliance because the majority of their clients are U.S. persons. However, the quality and timeliness of reporting packages varies among trustees. Some provide detailed year-end packages formatted for U.S. tax compliance. Others provide only raw account statements, leaving the CPA to extract and categorize the information. The grantor should establish early in the relationship what the trustee will provide and in what format.

The CPA prepares Forms 3520, 3520-A, and 8938, files them with the IRS, and may or may not also handle FBAR filing through the BSA E-Filing System. The grantor should confirm at the start of each tax year exactly which obligations the CPA will handle. If the CPA does not file FBAR, the grantor must file it independently or engage another professional to do so.

Requesting documentation from the trustee in January or February provides adequate lead time for the March 15 Form 3520-A deadline (or the September 15 extended deadline). Trustees operate in different time zones and may take several weeks to compile a complete package. Late requests compress the CPA’s preparation window and increase the risk of missed deadlines.

Selecting a CPA

Not all CPAs are equipped to handle Cook Islands trust compliance. The forms are specialized, the penalty exposure is high, and many general tax practitioners have never prepared Forms 3520 or 3520-A. Some CPAs decline foreign trust engagements entirely because of the complexity and professional liability involved.

A CPA handling Cook Islands trust compliance should have specific experience with Forms 3520, 3520-A, and 8938, as well as FBAR filing. They should understand the grantor trust rules under IRC sections 671 through 679, the mechanics of reporting foreign trust income on Form 1040, and the interaction between FBAR and Form 8938. They should also be familiar with the extension procedures (Form 7004 for Form 3520-A, Form 4868 for Form 3520) and the paper mailing requirements for IRS forms filed in Ogden, Utah.

The annual cost of compliance preparation for a Cook Islands trust typically ranges from $3,000 to $5,500, depending on complexity. This is a recurring annual expense that should be factored into the overall cost of maintaining the trust structure.

Penalty Mitigation and Voluntary Disclosure

Grantors who discover they have failed to file required forms have options, but the approach depends on the nature and severity of the failure and whether the IRS has already initiated contact.

For filers who have no unreported income and simply missed FBAR filings, the Delinquent FBAR Submission Procedures allow late filing through the BSA E-Filing System with an explanation. The IRS has stated that filers who come forward before being contacted and who have properly reported all income will generally not be penalized.

For filers with broader noncompliance, including missed Forms 3520, 3520-A, or 8938 along with unreported income, the Streamlined Filing Compliance Procedures offer a structured path. The streamlined domestic offshore procedures require a 5 percent miscellaneous offshore penalty. The streamlined foreign offshore procedures, for qualifying non-residents, impose no penalty. Both require a certification of non-willfulness.

For willful violations or cases involving potential criminal exposure, the IRS Voluntary Disclosure Program provides protection from criminal prosecution in exchange for full disclosure and substantial civil penalties.

These remediation options become unavailable once the IRS initiates an examination or contacts the taxpayer. The IRS has unlimited time to assess penalties for unfiled Forms 3520, 3520-A, and FBAR, so discovering noncompliance and hoping the IRS never notices is not a strategy. Taxpayers who identify past failures should consult experienced international tax counsel before filing any corrective returns.

Estimated Tax Payments

Because a Cook Islands trust is a foreign grantor trust, all trust income flows through to the grantor’s personal tax return. The trust itself does not pay U.S. income tax, and no withholding is applied to trust income at the source. This means the grantor is responsible for paying tax on trust income through estimated tax payments or through withholding on other income sources.

If the trust earns substantial investment income (dividends, interest, capital gains from the brokerage accounts held by the trustee), the grantor must make quarterly estimated tax payments to the IRS to avoid underpayment penalties. Estimated payments are due April 15, June 15, September 15, and January 15 of the following year. The amount owed depends on the grantor’s total income, deductions, and credits, not solely on trust income, but the trust income must be incorporated into the calculation.

Many grantors underestimate the estimated tax obligation in the first year of the trust because they are unfamiliar with reporting trust investment income on their personal return. The CPA should model the estimated tax impact when the trust is initially funded and adjust quarterly estimates as trust income becomes clearer.

State Tax Considerations

Federal reporting dominates the compliance discussion, but state tax obligations also apply. Most states follow federal tax treatment, meaning the grantor reports foreign grantor trust income on state returns the same way as on the federal return. The state taxes the income as if it were earned directly by the grantor.

Some states impose their own foreign trust or foreign account reporting requirements beyond the federal forms. California and New York, in particular, have additional disclosure obligations that apply to residents with foreign trust interests. California’s Franchise Tax Board has been active in requesting information about foreign trust arrangements, and New York’s Department of Taxation and Finance has its own reporting requirements that parallel but do not duplicate federal forms.

Grantors residing in states without income tax, such as Florida, Texas, and Nevada, avoid state income tax on trust income but may still face other state-level reporting or filing requirements depending on the nature of the trust’s assets and activities. Florida, where many Alper Law clients reside, does not impose personal income tax and has no separate foreign trust disclosure requirement, though grantors must still comply with all federal obligations.

Changes in the grantor’s state of residence can affect state compliance obligations. A grantor who moves from California to Florida eliminates California income tax on trust income going forward but may still owe California tax on income earned while a California resident. State tax planning should be coordinated with the attorney and CPA as part of the overall trust administration.

FATCA and International Information Sharing

The Foreign Account Tax Compliance Act (FATCA) imposes reporting obligations not only on U.S. taxpayers (through Form 8938) but also on foreign financial institutions that hold accounts for U.S. persons. Cook Islands banks and custodians that maintain accounts for Cook Islands trusts with U.S. grantors are required under FATCA to report those accounts to the IRS through intergovernmental information-sharing agreements.

This means the IRS receives information about Cook Islands trust accounts from two independent sources: from the grantor (through FBAR, Form 8938, and Forms 3520/3520-A) and from the foreign financial institution (through FATCA reporting). If the grantor files all required forms, the two sets of information should match. If the grantor fails to file, the IRS may still learn about the accounts through the institutional FATCA reports, creating an obvious discrepancy that can trigger examination.

The Cook Islands is a participant in international tax information-sharing frameworks, and Cook Islands trust companies comply with FATCA and related reporting requirements as part of their regulatory obligations. This reinforces the point that Cook Islands trusts provide asset protection through legal structure, not through secrecy. The IRS knows about the trust. The compliance obligation is to ensure the grantor’s filings are consistent with what the IRS already receives through other channels.

Compliance as a Long-Term Obligation

Cook Islands trusts are typically maintained for the grantor’s lifetime and sometimes beyond. A trust established at age 45 may require 40 or more years of annual compliance. Over that span, the grantor must file Form 3520-A, FBAR, Form 8938, and Form 3520 (for transfers and distributions) every year. A single failure in any year triggers penalties regardless of decades of perfect compliance before and after.

This long-term horizon makes professional continuity important. If the CPA retires or the grantor changes tax preparers, the successor must understand foreign trust reporting. If the Cook Islands trustee changes, the successor trustee must provide the same level of financial reporting to support U.S. compliance. Gaps in professional relationships create compliance risk.

Record retention is also critical. The statute of limitations for Forms 3520 and 3520-A penalties does not begin running until a complete and accurate form has been filed. If no form is filed, there is no statute of limitations. Maintaining copies of all filed forms, mailing receipts, account statements, and trustee correspondence for the life of the trust protects the grantor against future disputes.

The annual compliance burden is a real cost of offshore asset protection planning. It should be weighed honestly against the protection the trust provides. For grantors with significant litigation exposure and substantial assets, the compliance burden is a manageable administrative expense relative to the value at stake. For grantors with modest assets or limited exposure, the ongoing cost and complexity may outweigh the benefits.

For comprehensive information about Cook Islands trust structure, formation, and administration, return to the Cook Islands trust overview.