Research on social class inequality emphasizes the individual level mechanisms in maintaining and reinforcing inequality, but few studies have focused on the institutional mechanisms. We propose that classed wording (i.e., words more consistent with the independent and agentic norms of upper socioeconomic origin people) is an unresearched, institution-level mechanism of reproduction of class divides. In real world setting, we demonstrate that classed wording commonly employed in job descriptions can hinder upward mobility. Across two studies we demonstrate the existence of subtle but systematic differences in wording of job advertisements in the US. Results show that job advertisements in occupations dominated by people with higher social class origin employ greater agentic words (such as determined, assertive, autonomous, independent) than occupations dominated by those from lower social class origins. The effect persists even in white-collar jobs and the effect is not driven by the nature of jobs in which high and low socioeconomic background people work. The result is also robust to self-selection of low socioeconomic background people into certain jobs which they might believe to help upward mobility. Our results extend the discussion on the cultural barriers to upward mobility which are more subtle, not easily detectable, but leads to inequality.