Many policymakers assume that children's neighbourhoods shape their career trajectories, but the facts are otherwise. Challenges: (1) Because many children in poor postcodes have disadvantaged families, modelling the causal influence of neighbourhood socioeconomic status (SES) requires a comprehensive set of control variables measuring family background. (2) Adults can choose where to live, so dwelling in a high SES postcode is partially a consequence of occupational success, not a cause. Hence, we must focus on childhood postcode SES. (3) Random measurement error in postcode SES can bias estimates. Data: Large, representative national samples from the International Social Science Survey/Australia. OLS and structural equation models. Correlations between a person's childhood postcode SES and their education, adult occupational status (which robustly measures job quality, social status and permanent income) and family income are all modest, around r = .15. Net of family background (fathers' occupational status, fathers' class, mothers' employment, parents' culture, ethnicity, demographics and respondent's IQ) multivariate analyses show that growing up in a low SES postcode is only a slight disadvantage, which arises entirely because children there get about half a year less education than comparable children in high SES postcodes. Otherwise, there is no statistically significant childhood postcode disadvantage in career opportunities.