We investigate whether the comparability of financial statements changes after a switch from International Financial Reporting Standards (IFRS) in substance (i.e., content of IFRS) to IFRS in both substance and form (i.e., IFRS as issued by the IASB). While the substance of the accounting standards remains the same, form is added to the adoption in that it is now formally referred to as “IFRS as issued by the IASB.” We use data from South Africa, a country whose local generally accepted accounting practices (GAAP) was the same, word-for-word, as IFRS prior to the adoption of IFRS as issued by the IASB in 2005. We compare South African firms with firms in other countries, divided into two groups: mandatory IFRS adopters and non-adopters. We find evidence of increased comparability of financial statements of South African firms with both adopters and non-adopters. Furthermore, we find a global increase in the comparability of firms’ financial statements, consistent with market changes unrelated to IFRS adoption. However, an incremental increase in the comparability of financial statements of South African firms with the adoption of IFRS relative to non-adopting firms is consistent with benefits from South Africa’s addition of form to its existing in-substance adoption of IFRS. This increased comparability is also consistent with the benefits observed in the accounting amounts of firms from other adopting countries becoming more comparable with those of South African firms.