Corporations use global sustainability reporting principles, certifications, guidelines, and indices to promote corporate transparency. However, the effectiveness of adopting these global transparency approaches, either separately or collectively, in increasing firm value is as yet unclear. Thus, we examine whether different global transparency approaches engender different outcomes related to firm value and whether adopting a comprehensive or integrated global transparency approach could better enhance firm value. We use a sample comprising 6978 firm-year observations of firms listed in the United States (S&P 500), Canada (S&P-TSX 221), and the United Kingdom (FTSE 350) from 2013 to 2019. A fixed-effects regression model is then used to examine the primary associations in this study. This technique was complemented by a two-step dynamic generalised method of moment (GMM) model to overcome the expected endogeneity concerns. Our findings indicate that adopting global sustainability reporting principles, certifications, and an integrated global transparency approach is positively attributable to the market value of firms. In contrast, firms' adoption of international guidelines and environmental, social, and governance (ESG) ratings cannot predict the firm value in the study context. Our evidence implies that firms' adoption of an integrated global transparency approach adds the most value to those firms when compared with adopting a standalone transparency approach across the three sampled countries. Our study provides practical implications for policymakers and corporate managers and suggests avenues for future studies to build upon our findings.