IR35 Advice &
Contractor Accounting
from ACCA Specialists
Operating through a personal service company? Unsure whether your contract falls inside or outside IR35? Protax ACCA-certified accountants provide written contract reviews, status determination support, PSC accounting, and year-round IR35 compliance.
Tell us about your contract and we'll advise on your IR35 risk within one business day.
No obligation. ACCA-regulated. GDPR-compliant. We never share your details.
Protecting UK Contractors
from Costly IR35 Mistakes
Written IR35 Contract Reviews
We review your contract and actual working practices against all three primary IR35 tests, then provide a written opinion that documents your due diligence should HMRC ever raise an enquiry.
Request a Contract Review →
PSC Accounting & Salary Planning
Full limited company accounting, CT600, VAT, payroll, and tax-optimal salary and dividend structuring for outside IR35 contractors. We handle everything so you can focus on billing.
View Salary & Dividend Planning →
HMRC IR35 Investigation Defence
Received an IR35 enquiry? As HMRC-authorised agents we represent your PSC directly, managing all correspondence and compiling your evidence from day one of the investigation.
View Investigation Defence →What Is IR35 and Why Does It Matter for Your Contract?
IR35 is HMRC legislation that targets contractors who work like employees but use a limited company to pay less tax. A wrong determination can cost tens of thousands in backdated tax, National Insurance, interest, and penalties.
Since the 2021 Off-Payroll Working reforms, medium and large clients determine IR35 status for their contractors. However, the April 2025 small company threshold increase (turnover up to £15m) means thousands of businesses are newly reclassified as small, shifting responsibility back to the contractor's PSC. If this affects you, you must assess your own IR35 status from April 2026.
Inside vs Outside IR35, What Changes
| Factor | Outside IR35 | Inside IR35 |
|---|---|---|
| Tax treatment | Self-employed rates | Employee PAYE rates |
| NIC liability | Class 4 only | Class 1 Employer + Employee |
| Dividend planning | Available | Not available |
| Business expenses | Full deduction | Very limited |
| Employee rights | None | None (despite employee tax) |
| Estimated income impact | Full take-home | Typically 20-30% less |
The Three Core IR35 Tests HMRC Uses
IR35 status is assessed using three primary employment law tests. No single test is decisive. Most competitor accountants never explain these in plain English. We do.
Right of Substitution
Can you send a substitute in your place without the client vetoing it? A genuine, unfettered substitution right strongly indicates self-employment. If the client is paying for your personal services specifically, that points toward employment.
Control & Direction
Does the client control how, when, and where you work? Significant control over method points to employment. Contractors who set their own hours, work remotely, and determine their working method score better here.
Mutuality of Obligation
Is the client obliged to offer work, and are you obliged to accept it? Employment has ongoing obligation on both sides. Outside IR35 contractors work project by project with no guaranteed flow of assignments.
Additional factors HMRC examines
Beyond the three primary tests, HMRC also considers financial risk (do you bear the cost of correcting errors?), equipment provision, working for multiple clients, integration into the client's team, and overall financial exposure. A contract can pass all three primary tests and still be found inside IR35 if the overall picture resembles employment.
Complete IR35 & Contractor Accounting Services
We work with IT contractors, consultants, interim managers, and creative freelancers. Our ACCA-certified team covers every accounting and tax need your PSC has, alongside specialist IR35 contract review advice.
IR35 Contract Review & Written Opinion
We review your contract and working practices against all IR35 criteria and provide a written opinion on your status. We look beyond wording to how the engagement actually operates, which is HMRC's preferred approach in investigations.
Request Contract Review →PSC & Limited Company Accounting
Full annual accounts, CT600 corporation tax, VAT returns, RTI payroll, and director salary and dividend planning for your PSC. We manage all company filing obligations while you focus on contracting.
View Corporation Tax Service →Salary & Dividend Optimisation
For outside IR35 contractors, the right salary and dividend split saves thousands each year. We model the optimal remuneration structure for your income level, factoring in corporation tax, dividend allowance, and NI thresholds for 2026/27.
View Salary & Dividend Planning →HMRC IR35 Investigation Support
If HMRC opens an enquiry into your IR35 status, early representation is critical. We manage all correspondence, compile your evidence file, and represent your PSC throughout the investigation. See our full HMRC investigation defence service.
View Investigation Defence →Self Assessment for Contractors
Contractor self-assessment returns are more complex than most. Mixed income, umbrella periods, dividends, multiple directorships, and expenses all need careful handling. Our self-assessment service maximises every allowable deduction.
View Self Assessment Service →Umbrella vs Limited Company Advice
Not sure whether to use an umbrella company or your own PSC? We model actual take-home pay based on your day rate, contract duration, and IR35 risk. Inside IR35 does not automatically mean umbrella is better for your situation.
View Contractor Sector Page →- 3Primary tests HMRC uses to assess IR35 status
- 14k+Companies reclassified as small in April 2025
- 20-30%Typical income loss from inside IR35 finding
- £0Hidden fees, fixed-fee contractor accounting
IR35 Expertise That Goes Beyond Ticking a Box
Most accountants mention IR35. Few specialise in it. Protax provides written contract review opinions, working practice improvement advice, and direct HMRC representation if an investigation arises. We serve contractors across the UK through a fully remote service.
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Written Reviews, Not Verbal Opinions
We provide written IR35 status opinions covering both contract wording and actual working practices. This creates documented evidence of due diligence that protects you if HMRC raises an enquiry in the future.
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Working Practices Improvement Advice
A contract is only half the picture. We identify specific working practice changes that strengthen your outside IR35 position, such as exercising substitution rights, varying working hours, or structuring deliverables rather than time-based billing.
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Current on 2025/26 Small Company Changes
The April 2025 threshold changes affect many contractors right now. We help you identify which clients have been reclassified and what your status determination obligations are from April 2026 onward.
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Full PSC Accounting Under One Roof
IR35 advice in isolation is not enough. We handle your complete PSC accounting needs, from corporation tax and VAT returns to payroll and annual accounts, so your finances are as efficient as your contracts permit.
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Fully Remote, Nationwide Service
Contractors operate across the UK and move between clients in different cities. Our fully remote service means your ACCA accountant is accessible wherever your contract is based, with no office appointments required.
Is Your Contract Inside or Outside IR35? Get a Free Review.
Most UK contractors are not certain of their IR35 status and have no written evidence to support their position. A wrong determination can result in HMRC recovering years of backdated tax, NIC, interest, and penalties.
We provide a free initial IR35 assessment to new clients. Tell us about your contract and working arrangements and we'll advise on your risk level and recommended next steps.
- Free assessment of your current IR35 risk level
- Advice on whether your contract wording is IR35-safe
- Confirm whether the April 2025 changes affect your engagement
- Working practices review and improvement recommendations
- Fixed-fee quote for ongoing PSC accounting and IR35 compliance
Get Your Free IR35 Assessment
IR35 & Contractor Accounting FAQ
Get Your IR35 Contract Reviewed Before Your Next Engagement
A wrong IR35 determination can cost tens of thousands in backdated tax. A professional review from an ACCA-certified accountant takes days and gives you a written, documented position to rely on if HMRC ever asks questions.
- Written IR35 contract review opinion
- Working practice improvement recommendations
- Full PSC accounting and corporation tax
- Salary and dividend optimisation for outside IR35
- HMRC investigation representation if needed
- Fixed-fee service, no hourly billing surprises
Related services: Corporation Tax · Salary & Dividend · HMRC Investigation Defence