I do not practice in South Carolina. But, it is my understanding that in South Carolina it is unlawful for a person to wilfully give false, misleading, or incomplete testimony under oath in any court of record, judicial, administrative, or regulatory proceeding. It is further my understanding that a person who does is guilty of a felony and, upon conviction, must be fined in the discretion of the court or imprisoned not more than five years, or both. Please do not rely upon the foregoing without first confirming same with an attorney duly admitted to practice law in South Carolina. See” Section 16-9-10 fo the South Carolina Code of Laws @
In most states the claim of lying in court is called perjury. While you will have to consult the law in South Carolina, many states will penalize the 'lie' with at least as much time as the individual accused of the underlying crime is faced with. Thus, if someone lies about, say, a murder, the penalty upon conviction for that perjury could be up to life in prison. The 'lie' must usually be about something material, meaning something of importance to the facts of the underlying case.
All that said, it is an unfortunate truth that witnesses do frequently commit perjury. Again, please consult the statutes for the jurisdiction the matter occurred in for the actual penalty.
While each state law is different as it pertains to perjury and I am not admitted in your state, testifying under oath at a trial and then being charged with perjury is a serous matter. In order to find out the actual exposure you will have to speak with a criminal defense attorney in South Carolina.