Fla. Stat. § 198.14
To obtain an extension for filing a Florida return, the personal representative shall file with the department a copy of the federal extension request within 30 days after filing such request with the federal taxing authorities. If the federal taxing authorities grant an extension of time for filing a return, the department shall allow a like extension of time for filing if the personal representative files a copy of such federal extension with the department within 30 days after receiving an approved federal extension. An extension of time for filing a return shall not operate to extend the time for payment of the tax. If any person fails to file a return at the time prescribed by law or files, willfully or otherwise, a false or fraudulent return, the department shall make the return from its own knowledge and from such information as it can obtain through testimony or otherwise. Any such return so made by the department shall be prima facie good and sufficient for all legal purposes.
Fla. Stat. § 198.14