The deadline for filing annual reports in South Dakota depends on the type of entity. For corporations, the annual report must be filed by the last day of the month in which the corporation was established. For example, if a corporation was founded in April, the annual report would be due by April 30 of each year. For limited liability companies, the deadline for filing also aligns with the anniversary month of the LLC's formation. It is important to note that failing to file an annual report by the deadline may result in penalties or administrative dissolution. Individuals interested in specific dates or further details regarding the filing process may want to look on the South Dakota Secretary of State's website, where they can find current information and guidance on annual report requirements for various entities.