I am so very confused and please ignore my apparent ignorance but I am about to become a single parent to a 5 yr old and twins of 17 months. Things are very amicable but I am concerned how I will cope financially. I am about to apply for tax credits. Up until my April pay I and my husband received childcare vouchers through our employer but I understand you cannot claim both so have reduced them right down to £20 per month each from April pay packet. I will take this figure into account when completing my childcare costs. My question is, as tax credits are based on the previous year's income is it also based on the previous year's childcare or based on my current situation? I don't want to claim for something and then be told ive done it wrong and be in a situation where I owe a lot of money. I will be claiming from 23/04/2016 when my husband moves out of the marital home and our childcare vouchers will reduce down to £20 wef from end of April. Does this even make sense or am I worrying about nothing? Any help very gratefully received. I work 22.5 hours a week and earn an ok salary but certainly not enough to support 3 children and a mortgage without help (husband will be paying maintenance at going rate).