30 hours childcare eligibility

I’d like to start by saying that I know we are very lucky to be in the position we are before I get any negative comments.

I am trying to understand what income is included when applying for 30 hours childcare. I know any pension contributions are NOT included. Due to the nature of my husbands job however he receives a car allowance - is this amount included as eligible income?

He also has private medical insurance paid for by his employer, however for tax reasons this shows on his pay slip as an income and then the same amount again as a deduction.

Does anyone know what is included when making the childcare application? I can’t fond any advice online.

TIA