Cross-Border Solo Founder Compliance Checklist 2026

Compliance is not a single event. It is a calendar of structural obligations that accumulates with every jurisdiction touched, every entity formed, and every income stream established. For solo founders operating across borders, the obligation set is wider than any single advisor fully maps — because the obligations span tax, entity maintenance, financial reporting, and documentation domains that are administered by different authorities, on different timelines, with different penalty structures.

The structural gap that most cross-border founders face is not that they are deliberately non-compliant. It is that they have never seen the full inventory of what applies to them. A founder who files US taxes on time, maintains their LLC registration, and deposits income into a US bank account may believe they are structurally sound — while simultaneously having unfiled FBAR obligations, unreported foreign entity interests, missed state-level franchise tax deadlines, and documentation gaps that compound each year they remain unaddressed.

This is a map of what exists. Not advice on what to do about it — a structural inventory of the obligations, deadlines, and documentation requirements that cross-border solo founders encounter.

Annual compliance calendar

The timeline below covers US-centric deadlines with international reporting obligations layered in. The pattern across these deadlines is that they are staggered throughout the year, creating a continuous compliance surface rather than a single filing season.

Q1: January through March

| Deadline | Obligation | Form/Filing | Who It Applies To | |----------|-----------|-------------|-------------------| | January 31 | Issue 1099-NEC to US contractors | 1099-NEC | Any business that paid $600+ to a US non-employee | | January 31 | Issue 1099-MISC for rents, royalties, other income | 1099-MISC | Businesses making qualifying payments | | January 31 | W-2 to employees | W-2 | S-Corp owner-employees, any employees on payroll | | January 31 | File 1099s and W-2s with IRS/SSA | Transmittal forms | Same as above | | March 15 | S-Corp return due | Form 1120-S | S-Corp entities (or LLCs with S-Corp election) | | March 15 | Partnership return due | Form 1065 | Multi-member LLCs, partnerships | | March 15 | S-Corp election filing deadline | Form 2553 | LLCs electing S-Corp treatment for current year |

The structure indicates that Q1 is the densest compliance period for founders with employees, contractors, or S-Corp/partnership entities. Missing the January 31 deadlines carries per-form penalties that accumulate — $60 per form if corrected within 30 days, $120 per form if corrected by August 1, and $310 per form after that, with no maximum cap for intentional disregard.

Q2: April through June

| Deadline | Obligation | Form/Filing | Who It Applies To | |----------|-----------|-------------|-------------------| | April 15 | Personal income tax return | Form 1040 | US citizens and resident aliens | | April 15 | C-Corp return due | Form 1120 | C-Corporations | | April 15 | FBAR due (auto-extended to Oct 15) | FinCEN 114 | US persons with foreign accounts > $10K aggregate | | April 15 | First quarter estimated tax payment | Form 1040-ES | Self-employed individuals and pass-through owners | | April 15 | FATCA reporting (with tax return) | Form 8938 | US persons with specified foreign financial assets above threshold | | June 15 | Expat filing deadline (auto extension) | Form 1040 | US citizens and residents living abroad | | June 15 | Second quarter estimated tax payment | Form 1040-ES | Self-employed individuals and pass-through owners |

The April 15 deadline carries the most concentrated set of obligations. The distinction between FBAR and FATCA is a common point of confusion: both involve foreign financial reporting, but they are filed with different agencies (FinCEN vs. IRS), have different thresholds, and have different penalty structures. A founder may owe both on the same accounts. For a deeper look at FBAR specifically, see FBAR for Digital Nomads: The $10K Threshold Trap.

The June 15 automatic extension for expats is a filing extension, not a payment extension. Interest accrues on unpaid taxes from April 15 regardless of physical location.

Q3: July through September

| Deadline | Obligation | Form/Filing | Who It Applies To | |----------|-----------|-------------|-------------------| | September 15 | Third quarter estimated tax payment | Form 1040-ES | Self-employed individuals and pass-through owners | | September 15 | Extended S-Corp/Partnership return due | Forms 1120-S, 1065 | Entities that filed extensions |

Q3 is structurally lighter on deadlines but carries the weight of extended returns. Founders who filed extensions in March face their final deadline here. The pattern suggests that many founders treat extensions as routine, but extended returns filed close to the September 15 deadline leave minimal time for error correction before the October deadlines.

Q4: October through December

| Deadline | Obligation | Form/Filing | Who It Applies To | |----------|-----------|-------------|-------------------| | October 15 | Extended personal return due | Form 1040 | Individuals who filed extensions | | October 15 | FBAR final deadline | FinCEN 114 | US persons with foreign accounts (auto-extended from April 15) | | October 15 | Extended C-Corp return due | Form 1120 | C-Corps that filed extensions | | December 31 | Estimated tax safe harbor assessment | — | Planning for next-year estimated payments | | January 15 (next year) | Fourth quarter estimated tax payment | Form 1040-ES | Self-employed individuals and pass-through owners |

The October 15 deadline is the true final deadline for most individual filings. After this date, late filing penalties begin accumulating at 5% of unpaid taxes per month, up to 25%. The FBAR deadline on October 15 is the automatic extension — there is no further extension available.

International deadlines (common examples)

The following are illustrative of the additional calendar layer for founders with tax connections outside the US.

| Country | Filing Deadline | Key Obligations | |---------|----------------|-----------------| | United Kingdom | January 31 (following tax year) | Self Assessment return, payment of tax due | | Portugal | June 30 | IRS (Imposto sobre o Rendimento) annual filing | | Canada | April 30 (June 15 for self-employed) | T1 personal return, with payment still due April 30 | | Australia | October 31 (or later with tax agent) | Individual tax return | | Germany | July 31 (with advisor: end of February following year) | Einkommensteuererklarung | | Netherlands | May 1 | Inkomstenbelasting annual filing |

The structural observation: a founder who is US-based but has tax residency connections to another country faces two full compliance calendars running in parallel. The deadlines do not align. The forms do not reference each other. The information required overlaps but is not identical. Each jurisdiction operates as though it is the founder's only tax authority.

Entity maintenance checklist

Beyond tax filings, entities have their own maintenance obligations that are separate from income tax compliance. Missing these can result in entity dissolution, loss of good standing, or administrative penalties.

Annual report and franchise tax by state

| State | Annual Report | Franchise Tax | Due Date | |-------|--------------|---------------|----------| | Wyoming | Annual Report ($60, or $0 if assets < $300K) | No franchise tax | Anniversary of formation | | Delaware | Annual Report ($300 for LLC) | $300 annual LLC tax | June 1 | | California | Statement of Information ($20) | $800 annual franchise tax (LLC and S-Corp) | 15th day of 4th month after fiscal year end | | Florida | Annual Report ($138.75) | No state income tax | May 1 | | New Mexico | No annual report | No franchise tax | N/A | | Texas | Franchise Tax Report | 0.375%-0.75% on margin above $2.47M | May 15 |

The pattern across states is that formation cost is a one-time event, but entity maintenance is perpetual. A Wyoming LLC that costs $100 to form has a $60 annual obligation. A Delaware LLC has a $300 annual obligation. A California LLC — regardless of where the founder lives or where revenue is generated — has an $800 minimum franchise tax that applies even if the entity earns no income.

The structure indicates that founders who formed entities in multiple states (a common pattern among those who started with one formation agent and switched to another) may have parallel maintenance obligations for entities they no longer actively use but never formally dissolved.

Registered agent renewal

Every state that requires an entity to maintain a registered agent creates an annual renewal obligation. Registered agent services generally cost $100-$300 per year per state. If the registered agent lapses, the entity loses its ability to receive legal service of process — and in some states, the entity can be administratively dissolved after a period without a registered agent.

Business license and permit renewals

Local business licenses, professional permits, and industry-specific registrations each carry their own renewal cycles. These are jurisdiction-specific and not standardized. The structural risk is not the individual renewal — it is the accumulation across jurisdictions that creates a maintenance surface area the founder may not be tracking.

Tax filing obligations inventory

For a cross-border solo founder, the full set of potential US tax filing obligations extends well beyond the annual personal return.

Personal and entity returns

| Form | Purpose | Who Files | Deadline | |------|---------|-----------|----------| | Form 1040 | US individual income tax return | US citizens, resident aliens | April 15 (Oct 15 extended) | | Form 1040-NR | Non-resident alien income tax return | Non-resident aliens with US-source income | April 15 (Oct 15 extended) | | Form 1120-S | S-Corporation income tax return | LLCs with S-Corp election | March 15 (Sep 15 extended) | | Form 1065 | Partnership return | Multi-member LLCs | March 15 (Sep 15 extended) | | Form 1120 | C-Corporation income tax return | C-Corps | April 15 (Oct 15 extended) | | Schedule C | Sole proprietor / disregarded LLC income | Filed with Form 1040 | With personal return | | Schedule SE | Self-employment tax | Filed with Form 1040 | With personal return |

International information returns

| Form | Purpose | Who Files | Threshold / Trigger | Penalty for Non-Filing | |------|---------|-----------|--------------------|-----------------------| | FinCEN 114 (FBAR) | Foreign bank account report | US persons with foreign accounts | Aggregate max value > $10,000 | Up to $10K/account/year (non-willful); up to $100K or 50% balance (willful) | | Form 8938 (FATCA) | Statement of specified foreign financial assets | US persons | $50K+ end of year or $75K+ at any time (domestic); $200K/$300K (abroad) | $10,000 per failure, plus $10,000 per 30-day period after notice, up to $60,000 | | Form 5471 | Information return for US persons with respect to certain foreign corporations | US shareholders of controlled foreign corps | 10%+ ownership of foreign corporation | $10,000 per return, per year | | Form 8865 | Return of US persons with respect to certain foreign partnerships | US partners in foreign partnerships | Various categories of control/ownership | $10,000 per return, per year | | Form 3520 | Annual return to report transactions with foreign trusts | US persons with foreign trust transactions | Any reportable transaction | 35% of gross reportable amount | | Form 8621 | Information return by a shareholder of a PFIC | US persons who own shares in passive foreign investment companies | Any ownership | Depends on elections made |

The penalty structure for international information returns is notable: these are information-only filings that do not generate a tax payment, yet carry penalties that can exceed $10,000 per unfiled return. The structure indicates that the IRS treats the failure to provide information about foreign holdings with a penalty severity that is disproportionate to the tax impact of the filing itself. This pattern suggests that these filings serve an enforcement and transparency function beyond revenue collection.

State returns

State filing obligations depend on the founder's state of residence, the entity's state of formation, and any states where the business has nexus (a sufficient connection to trigger filing requirements). Common nexus triggers include physical presence, employees in the state, significant revenue from the state, and property in the state.

A founder who lives in California with a Wyoming LLC serving clients nationally may have California personal income tax obligations (based on residency), Wyoming entity maintenance obligations (based on formation), and potential nexus-based obligations in states where revenue concentration is high enough to trigger economic nexus thresholds.

Foreign reporting obligations

Founders living abroad face the domestic country's reporting obligations in addition to their US obligations. This creates a parallel compliance track that is administered independently.

UK Self Assessment. US citizens resident in the UK are subject to both US and UK tax on worldwide income. The UK Self Assessment return is due January 31 following the end of the tax year (which runs April 6 to April 5). UK tax on employment and self-employment income is assessed separately from investment income. The US-UK tax treaty provides relief mechanisms, but claiming treaty benefits requires proper disclosure on both returns.

Portugal IRS filing. Portugal taxes worldwide income for tax residents. The annual IRS filing is due by June 30. Portugal's Non-Habitual Resident (NHR) regime historically provided favorable tax treatment for qualifying foreign-source income, though the program has been modified and new applications are no longer accepted as of 2024. Founders who were granted NHR status before the cutoff retain their benefits for the 10-year period. The structure indicates that the post-NHR landscape changes the tax calculus for US founders considering Portugal as a base.

Canadian obligations. Canada taxes residents on worldwide income. The T1 return is due April 30 (June 15 for self-employed, but payment is still due April 30). Canadian foreign reporting requirements include Form T1135 (Foreign Income Verification Statement) for foreign property with a cost exceeding CAD $100,000 — a threshold that many cross-border founders exceed without realizing it.

The structural observation across all these scenarios: each country's compliance regime operates independently. The deadlines, forms, currencies, and reporting standards are not coordinated. A founder with US citizenship living in the UK with a Portuguese NHR status from a prior year and a Canadian corporation has four independent compliance tracks running simultaneously — each with its own calendar, its own penalties, and its own assumptions about what information the founder has already reported elsewhere.

Documentation maintenance

Beyond periodic filings, there is an ongoing documentation layer that is not deadline-driven but creates exposure when absent.

Transfer pricing documentation. If a founder has related entities in multiple jurisdictions — a US LLC and an Estonian OU, for example — any transactions between them (management fees, IP licensing, service agreements) are subject to transfer pricing rules. The documentation requirement is that prices between related parties be set at arm's length. This does not mean a formal transfer pricing study is always required, but contemporaneous documentation of the pricing rationale is the expected standard. The absence of this documentation does not trigger a filing penalty — it creates exposure when audited.

Operating agreement maintenance. An LLC operating agreement is not a file-and-forget document. Changes in membership, capital contributions, profit allocation, or management structure are reflected in the operating agreement. Founders who amended their business structure — adding a member, changing profit splits, changing management roles — without updating the operating agreement have a documentary gap between the actual structure and the documented structure.

Contractor agreements and W-8BEN collection. Founders who pay foreign contractors are required to collect Form W-8BEN (Certificate of Foreign Status) from each foreign payee. This form establishes the contractor's foreign status and determines whether withholding applies. Without it, the founder is technically required to withhold 30% of payments to foreign persons. The structural gap: many founders pay foreign contractors via Wise or PayPal without collecting W-8BEN forms, creating a documentation absence that becomes relevant if the payments are examined. For more on the documentation that authorities examine, see The Documentation Gap: What Authorities See.

Banking and financial records. Transaction records, bank statements, and payment processor reports form the evidential backbone of every filing. The general retention period for tax-relevant records is three years from the filing date (matching the standard IRS audit window), but extends to six years if there is a substantial understatement of income, and indefinitely for fraud or unfiled returns. FBAR records carry a five-year retention requirement. The pattern suggests that maintaining seven years of complete financial records covers most domestic scenarios, but international records with indefinite retention requirements for unfiled obligations create an asymmetry.

Invoice records and income source documentation. For founders invoicing clients in multiple countries, each invoice is a piece of the income source documentation that determines which jurisdiction has taxing rights over that income. The invoice currency, the client's location, the service delivery location, and the payment method all feed into income source determination. Founders who invoice through platforms (Upwork, Toptal, etc.) may have platform-generated records, but founders invoicing directly often have only their own records as documentation. For a detailed look at how income source documentation works, see What Your CPA Needs to See (And What You Probably Don't Have).

The compound effect of missed obligations

Each missed filing or documentation gap is individually manageable. The structural problem is compounding.

Penalty accumulation. A founder who missed FBAR filings for three years has three separate violations, each assessed independently. At up to $10,000 per account per year for non-willful violations, a founder with two reportable accounts has a potential penalty exposure of $60,000 — for an information filing that carries no tax payment.

Statute of limitations implications. The standard IRS audit window is three years from the filing date. But for international information returns (Forms 5471, 8865, 8938), the statute of limitations on the entire tax return remains open as long as the information return is unfiled. This means a founder who forgot to file Form 5471 in 2020 has an open statute of limitations on their entire 2020 return — not just the foreign corporation reporting, but every item on the return.

Downstream complications. Missed filings in one domain surface in others. A business sale requires representations about compliance history. A visa application may require tax return transcripts. A bank loan application requests entity documentation in good standing. A new business partner's due diligence examines the existing structure. Each of these events can make previously invisible compliance gaps suddenly visible — and the compressed timeline of these events rarely allows for orderly remediation.

Voluntary disclosure. The IRS offers programs for founders coming into compliance: the Streamlined Filing Compliance Procedures (for non-willful violations), the Delinquent International Information Return Submission Procedures, and the formal Voluntary Disclosure Practice. Each has different requirements, different penalty structures, and different levels of protection. The structural observation is that these programs exist precisely because the compliance gap is common enough to warrant a systematic remediation path.

What this means for your structure

The compliance landscape for cross-border solo founders is not a single obligation with a single deadline. It is a matrix of overlapping requirements, administered by different authorities, on different schedules, with different penalty structures for non-compliance. The surface area of this matrix expands with each jurisdiction touched, each entity formed, and each income stream established.

The most common structural gap is not deliberate non-compliance. It is incomplete awareness of what applies. A founder who has mapped their US tax filing obligations but not their FBAR obligations, their entity maintenance but not their state nexus exposure, their domestic compliance but not their foreign country reporting — that founder has a partial map of a full landscape.

The cost of completing the map before an inquiry is a fraction of the cost of completing it under pressure. The obligations exist whether or not they are mapped. The deadlines pass whether or not they are known. The penalties accumulate whether or not the founder was aware.

Visual: Cross-Border Compliance Calendar Overview

Key Takeaways

Cross-border compliance is a continuous calendar, not a single event — Q1 carries the densest deadline concentration (1099s, W-2s, entity returns, S-Corp elections), while penalties for missed information filings can accumulate independently at up to $10,000 per form per year.
International information returns (FBAR, FATCA, Forms 5471, 8865) carry penalties disproportionate to their tax impact, and an unfiled international information return holds the statute of limitations open on the entire associated tax return indefinitely.
Entity maintenance obligations (annual reports, franchise taxes, registered agent renewals) are separate from tax compliance and vary significantly by state — a California LLC owes $800 annually regardless of revenue, while a Wyoming LLC owes $60.
Founders with tax connections to multiple countries face parallel compliance calendars that operate independently — the deadlines, forms, and reporting standards are not coordinated across jurisdictions.
Documentation maintenance (transfer pricing rationale, W-8BEN collection, operating agreement updates, financial record retention) is not deadline-driven but creates structural exposure when absent during audits, business transactions, or visa applications.

References

IRS International Taxpayers Filing Requirements — IRS hub for all international filing obligations including FBAR, FATCA, and foreign entity reporting
FinCEN FBAR Filing Requirements — Official guidance on foreign bank account reporting thresholds and deadlines
IRS Streamlined Filing Compliance Procedures — Remediation program for non-willful international filing violations
IRS Estimated Tax Payment Guide — Quarterly estimated tax payment requirements and safe harbor rules

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