UK Umbrella Company PAYE Question

[RossTheNinja]

I was quoted by an umbrella company for a contract, and in their calculation they took the gross pay, then reduced it by both their umbrella fee and the Employer's NI to calculate the gross pay for Tax and NI. Am I crazy or are they? As I understand it, it should work in the same way as any other PAYE scheme, so was expecting the gross to be reduced by the umbrella company's fee,but maybe I'm missing something.
E.g.:

Umbrella Income - 400​

Ers NI - 28.12​

Umbrella Margin - 15​

---------------------------Gross Pay 356.87​

 

[Truemanbrown]

All umbrella companies do this. If the umbrella company was responsible for the employers NI, using your example, the umbrella company would lose £13.12 (Ers NI of £28.12 less Umbrella Margin of £15). They would soon be out of business.

 

[RossTheNinja]

Thanks for replying. I'm not questioning who pays it, I'm questioning the calculation.