30 Hours free Childcare support

Hi, this is the first time posting here, this question might have already posted but can't find the right answer anywhere.
I'm self- employed but don't make much money as need to jiggle between daughter, work and house as don't have family around, my husband works full time so we don't qualify for benefits, and I want to know -if someone can help- which income is used to classify for 30 hours free childcare, net income or taxable income?
Some information I've found mentions net income but other ones talk about taxable income and I'm not sure, When we applied for 30 hours last year, we got them as the way my business was going it looked that we were going to be ok but because of different reasons it didn't work as planned and although I did have an increase from last year, if I take net income I'm just classifying for it but if they use taxable I'm not.