If you are an American contractor providing services to UK end clients through your own UK Personal Service Company (PSC) or US-based LLC, IR35 US contractors UK applies through the Chapter 10 of ITEPA 2003’s off-payroll working regulations These rules shifted dramatically since April 2021, when the determination responsibility moved from the contractor to the […]
If you are an American contractor providing services to UK end clients through your own UK Personal Service Company (PSC) or US-based LLC, IR35 US contractors UK applies through the Chapter 10 of ITEPA 2003’s off-payroll working regulations These rules shifted dramatically since April 2021, when the determination responsibility moved from the contractor to the medium- and large-sized UK end client. Where IR35 applies (inside IR35), the engagement is taxed broadly like UK employment with PAYE Income Tax and Class 1 NIC deducted at source by the fee-payer, eliminating the tax efficiency of contracting through a limited company. Where IR35 does not apply (outside IR35), the contractor’s PSC can use normal Corporation Tax and dividend planning. The single point worth holding onto: US contractors face the additional cross-border complexity of US Form 1040 reporting on the same income, with foreign tax credit on Form 1116 absorbing UK Income Tax against US federal tax owed, and the US-UK Totalisation Certificate of Coverage on Form USA/UK1 eliminating US self-employment tax exposure prospectively for up to five years. Read on for the full breakdown.
The story usually plays out the same way. An American contractor moves to London, sets up a UK Limited company (PSC) on the recommendation of a UK accountant, and starts contracting for a UK bank, technology firm, or consultancy. Eighteen months in, the end client issues a Status Determination Statement classifying the engagement as inside IR35. The contractor’s net take-home falls by 20-35 percent overnight as PAYE Income Tax and Class 1 NIC are deducted at source. The US side continues to report the income on Form 1040, with no obvious mechanism to credit the new UK PAYE deductions cleanly.
This guide walks through how IR35 US contractors UK actually works in 2026, what the off-payroll working rules require of each party, and the specific cross-border moves that protect both the UK- and US-side tax positions. For broader cross-border guidance, see our US-UK cross-border tax advisory service.
IR35 is the popular name for the UK off-payroll working rules originally introduced by the Finance Act 2000 under Chapter 8 of ITEPA 2003, and significantly reformed by the Finance Act 2017 (public sector) and the Finance Act 2020 (private sector, effective April 2021) under Chapter 10 of ITEPA 2003. The rules apply where a worker provides services to an end client through an intermediary (typically a Personal Service Company, but also partnerships and certain other vehicles), and where the working arrangement would look like employment if the intermediary were stripped away.
The status determination test under the off-payroll working rules considers the same factors as the underlying employment status case law (Ready Mixed Concrete v Minister of Pensions and National Insurance 1968, Hall v Lorimer 1992, Autoclenz v Belcher 2011, and the long line of subsequent cases). The three core tests are mutuality of obligation (whether the end client must offer work and the worker must accept it), control (the degree of control the end client exercises over how, when, and where the work is done), and personal service (whether the worker must perform personally or can send a genuine substitute).
For IR35 US contractors in the UK, the framework applies wherever the contractor provides services to a UK end client through a UK PSC, a US-based LLC, or another intermediary structure. Where IR35 applies (inside IR35), the engagement is taxed as deemed employment. PAYE Income Tax and Class 1 NIC are deducted by the fee-payer (typically the end client or a recruitment agency in the supply chain) at the point of payment, eliminating the corporation tax and dividend structuring that PSC contractors traditionally relied on. Where IR35 does not apply (outside IR35), the contractor’s PSC operates under normal Corporation Tax rules, with director dividends typically replacing salary up to the dividend allowance threshold. The HMRC IR35 reference sits at https://www.gov.uk/topic/business-tax/ir35.
The April 2021 reform shifted the responsibility for status determination from the contractor to the medium- and large-sized UK end client. Small UK end clients (broadly meeting two of three Companies Act 2006 small company tests — turnover under £15 million as updated by Companies (Accounts and Reports) (Amendment) Regulations 2024, balance sheet under £7.5 million, fewer than 50 employees) retain the pre-2021 framework where the contractor’s PSC self-determines status. Most US contractors working through UK engagements above small client thresholds therefore face end-client-driven determinations rather than self-determination.
Three developments make 2026 a particularly active year for IR35 US contractors, UK planning.
First, the FA 2024 Companies Act 2006 threshold increases (effective for accounting periods starting on or after 6 April 2025) raised the small company test thresholds materially. Turnover threshold rose from £10.2 million to £15 million, balance sheet from £5.1 million to £7.5 million, and employee count remains at 50. The change means more UK end clients now fall within the “small” exemption and continue to push status determination back to the contractor’s PSC rather than running the end-client determination process themselves. US contractors engaging with UK SMEs more frequently face self-determination requirements again.
Second, HMRC compliance activity on IR35 has continued to expand through 2024 and 2025, following the first wave of post-reform Tax Tribunal cases (Atholl House Productions Ltd v HMRC 2022 Court of Appeal, Kickabout Productions Ltd v HMRC 2022, Adrian Chiles Basic Broadcasting case, Stuart Barnes case). The case law continues to refine the application of the Ready Mixed Concrete test in modern contracting scenarios, particularly for media, consultancy, and IT services engagements.
Third, the US-UK Income Tax Convention 1975 (as amended) Article 14 (Income from Employment) governs the tax treatment of deemed employment arising from inside-IR35 determinations. US contractors with inside-IR35 income face UK Income Tax via PAYE plus US federal income tax via Form 1040, with Form 1116 foreign tax credit in the general category basket absorbing UK PAYE against US federal tax owed. For deeper context, see our US-UK Treaty advisory service.
The status determination test for IR35 US contractors in the UK applies the same employment status case law that has developed since Ready Mixed Concrete v Minister of Pensions and National Insurance (1968). The three core tests are mutuality of obligation (does the end client have to offer work and does the worker have to accept it once offered), control (does the end client direct how, when, and where the work is done, or does the contractor exercise genuine professional autonomy), and personal service (must the contractor perform personally or can a genuine substitute be sent without the end client’s veto).
Additional supporting factors include financial risk (does the contractor invest in their own equipment, training, marketing, business insurance), provision of equipment (does the contractor use their own laptop, tools, vehicles), exclusivity (does the contractor work for multiple end clients or just one), integration into the end client’s organisation (does the contractor attend internal meetings, appear in internal directories, hold an end client email address), method of payment (fixed daily or hourly rate versus deliverable-based or project-priced), and right of substitution in practice rather than just on paper.
The CEST tool (Check Employment Status for Tax) at https://www.gov.uk/guidance/check-employment-status-for-tax provides HMRC’s standard determination framework. The CEST output is not binding and has been successfully challenged in several Tax Tribunal cases, but it provides a baseline indicator of HMRC’s likely view on a given engagement.
Where an engagement falls inside IR35, the fee-payer (typically the UK end client or recruitment agency in the supply chain) operates PAYE Income Tax and Class 1 NIC on the deemed employment payment. The deemed employment payment is broadly the contract fee minus a 5 percent allowance for the PSC’s running costs (under Chapter 8 self-determination) or the full contract fee under Chapter 10 end-client determination. PAYE deductions run at the standard UK Income Tax rates (20 percent, 40 percent, 45 percent), plus Employee Class 1 NIC at 8 percent up to the Upper Earnings Limit and 2 percent above it.
For a US contractor through a UK PSC with an inside-IR35 daily rate of £750 over 220 working days (£165,000 annual gross), the inside-IR35 PAYE deductions typically produce UK Income Tax and Class 1 NIC of approximately £58,000-£62,000 annually, depending on personal allowance entitlement. The PSC receives the net fee after fee-payer deductions, and the contractor can extract it as either further taxed salary or dividends from the residual after Corporation Tax.
Where an engagement falls outside IR35, the contractor’s PSC receives the full contract fee gross. The PSC then operates under normal Corporation Tax rules — UK CT at 25 percent on profits above £250,000, with marginal relief between £50,000 and £250,000, and 19 percent below £50,000 (the associated company division applies, as covered in our broader Corporation Tax guidance). The PSC’s director-shareholder typically extracts a small salary up to the National Insurance threshold, combined with dividends taxed at the dividend rates under the Income Tax Act 2007 (8.75 percent basic, 33.75 percent higher, 39.35 percent additional, with a £500 dividend allowance for 2025-26 and 2026-27).
Outside IR35 typically produces a net take-home of 65-75 percent of gross contract value for higher-rate contractors, compared to 50-60 percent for inside IR35 engagements. The difference of £15,000-£25,000 annually on a £150,000 gross contract drives the entire IR35 planning conversation. HMRC’s PAYE guidance for fee-payers is available at https://www.gov.uk/guidance/fee-payer-responsibilities-under-the-off-payroll-working-rules.
Step 1 — Identify whether the UK end client is small or medium/large under the Companies Act 2006. Small UK end clients (turnover under £15 million, balance sheet under £7.5 million, under 50 employees, meeting two of three) retain the pre-2021 Chapter 8 framework, under which the contractor’s PSC self-determines its status. Medium- and large-sized UK end clients operate the Chapter 10 framework, in which the end client issues the Status Determination Statement.
Step 2 — Request and review the Status Determination Statement (SDS) from medium- and large-end clients. Under Chapter 10 of ITEPA 2003, the end client must issue an SDS before or at the start of the engagement, and reissue it if circumstances change. The SDS must state the determination (inside or outside IR35) and the reasons supporting it. If you disagree with the SDS, you can request a Client-Led Disagreement Process under section 61T ITEPA 2003.
Step 3 — Run the CEST tool determination as a comparison check. The CEST tool at https://www.gov.uk/guidance/check-employment-status-for-tax provides HMRC’s standard framework. The output is not binding, but it provides a baseline indicator of HMRC’s likely view. Where CEST disagrees with the end client’s SDS, the engagement may need to be restructured or appealed.
Step 4 — Restructure the engagement to support outside-IR35 status if appropriate. Outside-IR35 positioning depends on genuine factors — real right of substitution exercisable in practice, genuine professional autonomy on how the work is done, financial risk, multiple concurrent end clients, deliverable-based pricing rather than time-and-materials, use of own equipment, and no integration into the end client’s organization chart. Contract drafting alone is rarely sufficient; the working reality must support the position.
Step 5 — Operate UK PSC accounting and Corporation Tax for outside-IR35 income. UK PSC handles bookkeeping, Corporation Tax (CT600), VAT registration if turnover exceeds the £90,000 threshold, payroll for any salary payments, and dividend documentation. The director-shareholder extracts a mix of a small salary and dividends optimized against the personal Income Tax bands.
Step 6 — Coordinate with US-side Form 1040 reporting and foreign tax credit positioning. US citizens and Green Card holders include the UK PSC profit on the US side. For US individuals owning the PSC alone, GILTI under IRC Section 951A applies to the UK PSC’s tested income, with a Section 962 election potentially appropriate to access the 21 percent corporate rate and to absorb foreign tax credits. For inside-IR35 income, the deemed employment income reports on Form 1040 as wages with Form 1116 general category basket foreign tax credit absorbing UK PAYE and Class 1 NIC against US federal tax.
Step 7 — Apply for the US-UK Totalisation Certificate of Coverage on Form USA/UK1. The Certificate exempts the contractor from US self-employment tax under IRC Section 1401 at 15.3 percent for up to 5 years, where the contracting income would otherwise be subject to US self-employment tax (typically applicable to US contractors operating through US LLCs treated as disregarded entities or through US S-corporations). The HMRC Totalisation reference sits at https://www.gov.uk/government/publications/national-insurance-certificate-of-continuing-liability-ca-3837.
A 39-year-old US citizen moved from Austin to London in 2020 and set up a UK Personal Service Company through which he provided software architecture services. His primary engagement was with a top-five UK retail bank at a daily rate of £825 over 220 working days, generating annual gross contract revenue of £181,500 through the PSC. A secondary engagement with a UK fintech scale-up contributed an additional £35,000- £60,000 annually.
In early 2025, the UK bank issued a Status Determination Statement classifying the engagement as inside IR35 under Chapter 10 of ITEPA 2003. The bank cited integration factors (the contractor attended weekly internal team standups, used a bank-issued laptop, sat in the bank’s internal architect directory, reported to a named bank line manager) and limited right of substitution in practice. The fintech engagement remained outside IR35 under self-determination because the fintech client met the Companies Act 2006 small company test.
The US contractor’s net take-home from the bank engagement fell from approximately £108,000 (outside IR35, net through a PSC) to approximately £88,000 (inside IR35, net via PAYE deductions by the bank’s fee-payer chain) once the SDS took effect — a £20,000 annual reduction.
We took the engagement in mid-2025 with three workstreams—first, the IR35 status review for the bank engagement. We reviewed the contract terms and the working reality (interviewing the contractor about his day-to-day routine), and ran a fresh CEST tool determination. The output supported the bank’s inside-IR35 finding, given the integration factors. We confirmed the SDS was correct and there was no realistic appeal route through the Client-Led Disagreement Process. Second, the fintech engagement structuring to preserve outside-IR35 positioning. We worked with the fintech client and the contractor on contract drafting and on alignment of working realities — a genuine right of substitution exercisable in practice, project-based deliverable pricing rather than time-and-materials, no integration into the fintech’s internal organization chart, and use of the contractor’s own equipment. The fintech engagement remained outside IR35 with proper documentation. Third, the cross-border US-side coordination. The inside-IR35 bank income reported on Form 1040 as US wages with Form 1116 general category foreign tax credit absorbing the UK PAYE and Class 1 NIC. The outside-IR35 fintech income flowed through the UK PSC with normal Corporation Tax and dividend extraction, with the US side picking up the GILTI inclusion on the UK PSC profit and Section 962 election applied to access the 21 percent corporate rate with foreign tax credit on UK CT paid.
The integrated outcome was UK Income Tax and NIC totaling approximately £74,000 on combined gross contract revenue of approximately £230,000 (£181,500 bank inside IR35 plus £48,500 fintech outside IR35), producing net UK income of approximately £156,000. US-side Form 1040 with foreign tax credit absorption resulted in a net additional US federal tax of approximately $1,800 (NIIT exposure on the UK PSC dividend distribution; all other US tax absorbed by the foreign tax credit). Combined effective rate roughly 33 percent on the gross contract revenue — manageable given the inside-IR35 bank engagement’s structural tax treatment.
The case illustrates the standard pattern for US contractors working across a mix of inside and outside IR35 engagements. The bank engagement could not be repositioned without changing the underlying working reality. The fintech engagement preserved its outside-IR35 status through proper structuring. The cross-border US-side coordination prevented any double taxation on the inside-IR35 income.
Assuming US citizenship or ownership of a US-based LLC exempts the engagement from IR35. IR35 applies based on the end client’s location and the working arrangement, not the contractor’s nationality or the contractor’s location of ownership. A US contractor operating through a US LLC providing services to a UK end client still falls within IR35 scope if the engagement would look like UK employment if the intermediary were stripped away.
Relying on contract drafting alone to support outside-IR35 status. The status determination considers the working reality rather than just the contract terms. A contract stating that the contractor has the right to substitute, exercises full control over how the work is done, and bears financial risk does not produce outside-IR35 status if the working reality contradicts those terms. Working reality alignment is essential.
Missing the Companies Act 2006 small company test changes from April 2025. The FA 2024 threshold increases (turnover from £10.2m to £15m, balance sheet from £5.1m to £7.5m, employee count remains at 50) mean more UK end clients now fall within the small client exemption. Contractors engaging with UK SMEs need to confirm the end client’s size status and apply the appropriate framework (Chapter 8: self-determination for small clients; Chapter 10: end-client determination for medium and large clients).
Ignoring US-side reporting on UK PSC profit or inside-IR35 income. US citizens and Green Card holders report worldwide income on Form 1040 regardless of UK residence or UK PSC ownership. UK PSC profit triggers GILTI inclusions under IRC Section 951A and Form 5471 reporting, per US shareholder, per CFC, per year. Inside-IR35 income reports as US wages on Form 1040 with foreign tax credit absorbing UK PAYE.
Missing the US-UK Totalisation Certificate of Coverage where applicable. US contractors operating through US LLCs treated as disregarded entities, or through US S-corporations, may be subject to US self-employment tax under IRC Section 1401 at 15.3 percent on the same income. The Form USA/UK1 Certificate from HMRC eliminates this exposure prospectively for up to five years. Contractors operating through UK PSCs typically do not face US self-employment tax because the UK PSC is treated as a UK corporation for US purposes. However, the Certificate remains relevant for any direct contracting income.
Failing to request the Status Determination Statement before engagement starts. Under Chapter 10 of ITEPA 2003, medium- and large-end clients must issue the SDS before or at the start of the engagement. Contractors who start an engagement without the SDS face uncertainty on tax treatment and limited recourse if the determination changes mid-engagement. The HMRC off-payroll working rules technical guidance sits at https://www.gov.uk/guidance/understanding-off-payroll-working-ir35.
Jungle Tax holds CIOT (Chartered Institute of Taxation) credentials and ACCA membership, with team members holding IRS Enrolled Agent status for US-side representation. Our team handles UK PSC accounting, IR35 status review and contract drafting alignment, CEST tool determinations, Status Determination Statement review and Client-Led Disagreement Process management, UK Corporation Tax with CT600 returns and dividend planning, US Form 1040 with Form 1116 foreign tax credit, Form 5471 reporting on UK PSCs as CFCs, Section 962 elections, and the US-UK Totalisation Certificate of Coverage applications through HMRC.
A typical engagement for a US contractor operating through a UK PSC runs across three streams. First, the IR35 status diagnostic — reviewing each contract and the working reality, running CEST tool determinations as comparison checks, reviewing any Status Determination Statements issued by medium- and large-end clients, and identifying restructuring opportunities to preserve outside-IR35 status where appropriate. Second, the UK PSC and personal tax workflow — UK PSC accounting and Corporation Tax return preparation, dividend planning against personal Income Tax bands and the £500 dividend allowance, Self Assessment for the director-shareholder, and inside-IR35 income reconciliation against fee-payer PAYE deductions. Third, the US-side integrated coordination — Form 1040 with Schedule B for UK PSC dividends and Schedule E for any rental or partnership income, Form 1116 foreign tax credit modelling across general category basket (for inside-IR35 wages-equivalent income) and passive basket (for UK PSC dividends), Form 5471 reporting on the UK PSC as a CFC, Section 962 election where appropriate, and the US-UK Totalisation Certificate of Coverage application where applicable.
For broader cross-border guidance, see our US-UK cross-border tax advisory service and our self-employed and contractor tax service. Contact info@jungletax.co.uk to discuss your situation.
Three points to take away. First, IR35 US contractors UK applies wherever an American contractor provides services to a UK end client through a Personal Service Company or other intermediary structure, with the three core status tests (mutuality of obligation, control, personal service) determining whether the engagement falls inside or outside IR35. Inside-IR35 engagements lose approximately 15-25 percent of net take-home compared to outside-IR35 positioning, making accurate status determination the single highest-value compliance decision in each engagement. Second, the April 2021 Chapter 10 reform shifted determination responsibility to medium and large UK end clients, and the FA 2024 small company threshold increases (turnover from £10.2m to £15m effective April 2025) mean more UK SMEs now fall within the small client exemption and push determination back to the contractor’s PSC. Third, US-side coordination requires Form 1040 reporting of UK PSC profit (with GILTI inclusions on the PSC as a CFC and Section 962 election typically appropriate), foreign tax credit absorption on Form 1116 across the general and passive baskets, and the US-UK Totalisation Certificate of Coverage on Form USA/UK1 to eliminate US self-employment tax exposure where applicable. Speak to a Jungle Tax adviser today — contact us at info@jungletax.co.uk or visit https://www.jungletax.co.uk/.
Yes. IR35 applies based on the end client’s location and the working arrangement, rather than the contractor’s nationality or location. A US contractor providing services to a UK end client through any intermediary (UK PSC, US LLC, US S-corporation, partnership) falls within IR35 scope if the engagement would look like UK employment if the intermediary were stripped away. The HMRC off-payroll working rules technical guidance sits at https://www.gov.uk/guidance/understanding-off-payroll-working-ir35.
Medium and large UK end clients are responsible for issuing a Status Determination Statement under Chapter 10 of ITEPA 2003. Small UK end clients (meeting two of three Companies Act 2006 small company tests — turnover under £15m, balance sheet under £7.5m, fewer than 50 employees from April 2025) retain the pre-2021 Chapter 8 framework, under which the contractor’s PSC self-determines its status. The size assessment is made against the end client’s most recent statutory accounts.
The three core tests from Ready Mixed Concrete v Minister of Pensions and National Insurance 1968 are mutuality of obligation (whether the end client must offer work and the worker must accept it), control (the degree of control the end client exercises over how, when, and where the work is done), and personal service (whether the worker must perform personally or can send a genuine substitute). Supporting factors include financial risk, equipment provision, exclusivity, integration into the end client’s organization, and payment method.
Inside-IR35 income is taxed as deemed employment in the UK with PAYE Income Tax and Class 1 NIC deducted by the fee-payer at the point of payment. For US citizens, the income is reported on Form 1040 as US wages, with the Form 1116 foreign tax credit in the general category basket absorbing UK PAYE and Class 1 NIC against US federal tax owed on the same income under Article 14 (Income from Employment) of the US-UK Income Tax Convention 1975. The IRS Form 1116 reference sits at https://www.irs.gov/forms-pubs/about-form-1116.
Yes, through the Client-Led Disagreement Process under section 61T ITEPA 2003. The contractor or the deemed employer can submit reasons for disagreement to the end client, who must respond within 45 days either confirming the original determination with reasons or issuing a revised SDS. If the disagreement is not resolved at the end client level, the engagement may continue under the disputed determination. At the same time, the parties consider their wider options, including potential Tax Tribunal proceedings.
For most US contractors providing services regularly to UK end clients, a UK PSC is typically the cleaner structure because it places the intermediary in the same jurisdiction as the end client and the underlying work. A US LLC operating across borders exposes the same income to both US and UK tax and complicates IR35 status determination. The UK PSC is treated as a UK corporation for US purposes (CFC reporting is required on Form 5471, with a potential Section 962 election), but the operational structure is significantly simpler.
Inside-IR35 income subject to UK PAYE Income Tax and Class 1 NIC does not attract US self-employment tax because the income is treated as employment for tax purposes. Outside-IR35 income flowing through a UK PSC does not directly attract US self-employment tax because the PSC is a corporation; the US contractor receives dividend or salary distributions, which are reported separately. US contractors operating through US LLCs treated as disregarded entities or through US S-corporations may face US self-employment tax exposure, which the US-UK Totalisation Certificate on Form USA/UK1 can eliminate prospectively for up to five years.
Yes — this is a core practice area for US contractors operating in the UK market. We handle IR35 status diagnostic and CEST tool review, contract drafting alignment to support outside-IR35 positioning where appropriate, Status Determination Statement review and Client-Led Disagreement Process management, UK PSC accounting and Corporation Tax returns, dividend and salary planning, US Form 1040 with Form 1116 foreign tax credit across general and passive baskets, Form 5471 reporting on the UK PSC as a CFC, Section 962 elections, and the US-UK Totalisation Certificate of Coverage applications. Fees for the integrated UK-US contractor engagement typically range from £3,500 to £8,500 annually, depending on engagement complexity. Contact info@jungletax.co.uk to discuss your situation.
