evidence: This paper extends the UK studies examining costs in a number of ways. It combines all the parameters of a fully universal full-time high-quality system for all pre-school children, that is increasing free provision as well as pay and qualifications. It also adds essential dimensions to understand the fuller short-term economic effects, based on the findings in other countries. The paper extends the method developed for Turkey, firstly by looking at the wider employment effects, i.e. not just indirect but also induced employment creation in the wider economy and, secondly, by estimating fiscal revenue generated, not just from income and expenditure taxes but also from interactions with the means-tested benefit system, using a reputable tax-benefits microsimulation tool for the UK, the UKMOD tool. It also provides estimations of longitudinal fiscal revenues stemming from increased earnings of mothers over time, following the findings of persistent employment effects of universal childcare policies in Norway and Quebec (Andresen & Havnes, 2018; Lefebvre et al., 2009). Unlike these studies which examined a natural experiment of a policy that had taken place, this paper focuses on appraising potential effects of government childcare policy by modelling various scenarios of take-up and pay rises. [...] The choice of starting the provision at six months implies a shorter maternity leave than currently available in the UK, more in line with other western European countries but still above the EU minimum of 14 weeks. [...] Full-time equivalent - GDP: