-
An umbrella company basically becomes your employer so they're paying all the correct tax and national insurance etc at source, the whole point of being inside ir35 is that you're paid paye and not invoicing.
You might not need to go through an umbrella company if their payroll will pay you paye but à lot of places won't do it for the hassle so just farm everything off to umbrella companies.
Is an umbrella company a very specific thing or just a colloquialism? What if another (friendly) limited company billed on my behalf and I gave them 5% or something? Would that be legal? Isn't that basically what an umbrella company is?