The Securities and Exchange Commission published an analysis of custom tags (extensions) used by IFRS filers on Forms 20-F, 20-F/A, 40-F and 40-F/A from January 2017 to December 2019. The analysis compares the use of custom tags on financial statements only, to custom tag rates for financial statements plus footnotes. The latest figures for 2019 indicate extension rates of 19% for financial statements, and 42% for statements plus footnotes. The use of custom tags is trending higher, from 17% in 2018, to 19% in 2019 for statements; and from 41% to 42% for footnotes.
The overall tag rate (for statements plus footnotes) for IFRS filers is slightly higher than custom tag rates for GAAP filers, according to a similar SEC analysis. In 2019, GAAP filers had a custom extension rate of 17% in 2019 (versus 19% for IFRS filers).