S.C. Code § 12-37-970
The assessment for property taxation of equipment, furniture and fixtures, and manufacturers' real and tangible personal property, and the machinery, equipment, furniture, and fixtures of all other taxpayers required to file returns with the South Carolina Department of Revenue for purposes of assessment for property taxation, must be determined by the department from property tax returns submitted by the taxpayers to the department on or before the last day of the fourth month after the close of the accounting period regularly employed by the taxpayer for income tax purposes in accordance with Chapter 7 of this title. The department by regulation shall prescribe the form of return required by this section, the information to be contained in it, and the manner in which the returns must be submitted. Every taxpayer required to make return to the department of property for assessment for property taxation must make the return to the department not less than once each calendar year. Whenever by a change of accounting period, or otherwise, more than one accounting period ends within any one calendar year, the taxpayer must make one such return within the prescribed time for filing following the end of each of the accounting periods and the department shall determine the assessment from the return setting forth the greatest value.
When property required to be returned as herein provided is sold after the end of the seller's accounting year and before January first next ensuing and when the purchaser's accounting year ends after the seller's and before January first next ensuing, the property must be returned by the seller as of the end of his accounting period. The purchaser is not required to list and return the property as of the close of his accounting period during the calendar year of sale. The seller and the purchaser are jointly and singularly liable for the tax that is due and payable by reason of this provision. The provision of this section does not apply to motor vehicles licensed for use on public highways.
When property required to be returned as provided in this section is sold before the end of the seller's accounting year and before January first next ensuing and when the purchaser's accounting year ends before the date of purchase and before January first next ensuing, the property must be listed and returned by the taxpayer holding title as of December thirty-first and is liable for the tax for the ensuing year.
The Department of Revenue shall forward the assessments prepared as a result of the returns submitted pursuant to this section to the appropriate local taxing authorities no later than August fifteenth of the applicable tax year.
S.C. Code § 12-37-970