We use data multinational firms provide to the Internal Revenue Service regarding their foreign subsidiary locations to explore whether some firms fail to publicly disclose subsidiaries in some countries, even when the subsidiaries are significant and should be disclosed per Security and Exchange Commission rules. The propensity to omit significant subsidiaries is especially strong when subsidiaries are in tax havens and when the firm is more highly scrutinized by the media, suggesting firms believe there are reputational costs associated with operations in tax havens. Additionally, we find evidence that firms omitting significant subsidiaries are more likely to misstate their financial results and are more likely to receive an SEC comment letter as compared to firms that do not omit significant subsidiaries. These results suggest that subsidiary omission may be indicative of firms’ broader disclosure and accounting choices.