How much more do I take home outside IR35 at £650/day?
At £650/day over 220 billable days (£143,000 contract revenue), outside IR35 nets you £84,808 per year through a limited company, versus £76,346 per year inside IR35 via an umbrella. That is a difference of £8,462 per year (11.1% more), before accounting for accountancy fees you'd pay either way.
