Inside vs Outside IR35: The Real Difference for Contractors
A clear comparison of inside vs outside IR35 — tax treatment, employment rights, a worked example and what rate makes inside worth it.
In This Article
Inside vs Outside IR35: What Is the Difference and Why It Matters
Inside and outside IR35 describe two different tax outcomes for the same kind of work, and which one applies to you changes how much of your contract income you actually keep. Get it wrong, or misunderstand which one you're operating under and the financial gap can run into thousands of pounds a year. This guide breaks down what each status means day to day, shows a worked example and covers the questions contractors ask most once a determination has landed in their inbox.
What Does Inside vs Outside IR35 Actually Mean?
"Inside IR35" means HMRC treats your contract as disguised employment for tax purposes, even though you're working through your own limited company. "Outside IR35" means HMRC accepts you're genuinely trading as an independent business and you're taxed accordingly.
The label isn't about your job title, your industry or how long you've been contracting. It's a per-engagement assessment based on how the working relationship actually functions — control over your work, whether you could send a substitute and whether there's an ongoing obligation to keep offering and accepting work. We've covered those tests in detail in our guide to how IR35 works, so this post focuses on what the outcome means for you once a determination has been made.
Inside IR35: What It Means for You
If your engagement is inside IR35, the fee-payer deducts Income Tax and National Insurance from your pay before it reaches you, similar to a standard payslip.
- Tax and National Insurance are deducted at source, so there's no year-end surprise but also less flexibility in managing your income.
- Business expenses are much harder to claim, since you're taxed as though on the client's payroll.
- You get none of the employment rights that come with employee status — no holiday pay, no sick pay, no pension contributions, no protection from unfair dismissal — despite paying tax at a broadly similar rate.
That last point catches a lot of contractors off guard. Being inside IR35 doesn't make you an employee in any legal sense. You're taxed like one, without gaining the protections that come with actually being one.
Outside IR35: What It Means for You
If your engagement is outside IR35, you're treated as a genuine business. Your limited company invoices the client, gets paid in full with no deductions and you manage your own tax position from there.
- You can pay yourself through a mix of salary and dividends, generally more tax-efficient than an equivalent PAYE salary.
- Legitimate business expenses, equipment, travel between engagements, professional insurance, are properly claimable.
- You carry more commercial risk yourself, since being genuinely outside IR35 means acting like an independent business rather than a guaranteed income stream.
Outside status generally means a noticeably higher take-home income for the same contract value, but comes with more responsibility for managing your own tax affairs correctly and more scrutiny if HMRC ever questions the determination.
Inside vs Outside IR35 at a Glance
| Feature | Inside IR35 | Outside IR35 |
|---|---|---|
| How you're paid | Tax and NI deducted at source | Paid gross to your company |
| Take-home pay | Lower, for the same contract value | Higher, for the same contract value |
| Business expenses | Very limited | Claimable |
| Employment rights | None | None (you're a business, not an employee) |
| Who typically decides | The client, if medium or large | The client or your own company, depending on size |
| Risk you carry | Lower commercial risk | Higher commercial risk, more responsibility |
A Worked Example: Same Contract, Two Very Different Outcomes
These figures are simplified for clarity and will vary depending on your expenses, pension contributions and pay structure, so treat this as a shape of the difference rather than a number to plan around.
£60,000 Annual Contract Comparison
Net Take-Home Pay (Salary + Dividend Structure)
Net Take-Home Pay (Full PAYE Deductions at Source)
That roughly £8,000 gap tends to widen as day rates rise, since dividend tax efficiency becomes more pronounced at higher income. A contractor accountant can run the real numbers for your specific contract rather than relying on an illustrative example.
Offered an Inside IR35 Role? Here's What Rate Makes It Worth It
If a client offers a contract already determined inside IR35, the natural question is whether the rate on the table is worth it compared to holding out for outside-IR35 work.
A common approach is to work out the percentage gap between inside and outside pay on a comparable contract, then use that as a starting point for negotiation. If an outside contract nets noticeably more at the same headline rate, it's reasonable to ask for a meaningful uplift, sometimes in the region of 20 to 30 percent, to make the inside role financially comparable.
That figure isn't a fixed rule, just a common starting point and the right number depends on your expenses, other income and how much you value the reduced admin that comes with inside IR35 work. Some contractors accept a smaller uplift for that simplicity; others hold out for outside work specifically because the numbers matter more. Going in with a clear sense of the gap means negotiating from an informed position rather than guessing.
Can Your Status Change Between Contracts, or Mid-Contract?
Yes, and this trips up contractors who assume status is a fixed personal label rather than something assessed per engagement. You can be outside IR35 on one contract and inside on the next, even with the same client, if the working practices differ.
Status can also shift within a single contract. If your role changes, more day-to-day direction, a loss of your substitution right, an ongoing expectation of continuous work replacing what was originally a defined project, the determination should be revisited. We've covered this, along with the full process and appeal rights, in our guide to IR35 rules.
Common Misconceptions About Inside and Outside IR35
"Outside IR35 is always better."
Not necessarily. Outside status carries more risk and for some contractors, particularly short-term or those valuing simplicity, an inside role at the right rate can make sense.
"My agency decides my status."
Responsibility sits with the client (if medium or large) or your own company (if the client is small), not typically the agency.
"Once outside, I stay outside for future contracts too."
Status is assessed per engagement, even with a familiar client.
"Inside IR35 means I'm now an employee."
You're taxed similarly, but you gain no employment rights as a result.
How a Contractor Accountant Helps You Plan Around This
Working out whether a contract genuinely makes sense inside or outside IR35 and what rate would make either option worthwhile, is easier with an accountant who works with contractors regularly rather than modelling it yourself from general examples. A specialist can run the actual numbers for your situation, review whether a contract's working practices genuinely support the status you've been given and help you negotiate from real figures rather than a rule of thumb.
If you're contracting in or around Bristol, an accountant who understands the local market can also help when negotiating rates that reflect what's realistic in your area. Take a look at our contractor accountant services if you'd like this handled properly.
Conclusion
Inside and outside IR35 aren't just labels, they determine how much of your contract income actually reaches you, and getting the distinction right matters more than most contractors realise until they see the numbers side by side. The core difference comes down to how you're taxed and what risk you're taking on: inside means employee-style deductions with none of the employee protections, outside means genuine business status with more control and more responsibility.
Since status is assessed per engagement rather than fixed to you personally, it's worth checking it fresh on every contract rather than assuming last time's outcome still applies. When the numbers or the decision get complicated, that's exactly where a specialist contractor accountant earns their fee.
Unsure about your IR35 status or contract rate?
Our specialist contractor accountants evaluate your working practices and run accurate take-home pay calculations for both inside and outside roles.