Architecture Social
Contract / IR35 calculator.
Compare inside-IR35 and outside-IR35 contractor income to understand the tax and take-home difference.
Calculator
Contract / IR35 calculator.
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Annual revenue
£103,500
Best: Outside IR35
- Permanent
- £45,357 (24.4% tax)
- Outside IR35
- £63,918 (32.0% tax)
- Inside IR35
- £63,136 (44.5% tax)
- Umbrella
- £62,556 (44.4% tax)
FAQs
Common questions.
Practical answers for the questions people ask about this tool.
Does this tell me whether I am inside or outside IR35?
No, and nothing on a calculator can. IR35 status depends on the reality of the working arrangement — control, substitution, mutuality of obligation and how the engagement actually runs day to day. This tool shows what each status does to your take-home once someone else has determined it. Use HMRC CEST and take professional advice for the determination itself.
Who decides my IR35 status?
For medium and large private-sector clients and all public-sector bodies, the client decides and must give you a Status Determination Statement with reasons. For small clients, the responsibility stays with your own company. If you disagree with a determination, the client has to consider your challenge.
Why is the inside-IR35 figure so much lower?
Inside IR35 the engagement is taxed broadly like employment, so income tax and National Insurance apply to most of the fee, and the expenses you could otherwise claim largely fall away. Employment rights do not automatically follow, which is why an inside rate is usually negotiated higher than the outside equivalent.
Next steps
Ready to explore roles or pay?
Use these figures as a guide, then browse architecture jobs or check salary bands before making a move.