Do you have to be a licensed contractor in order to file a mechanic lien

The short answer is Yes you usually do. The longer answer is that it depends on what type or work or what material you supplied to the project. If South Carolina LLR requires you to be licenesed or registered to do the work than you must have that license or registration in order to file a lien. However, if you aren't required to be licensed (an easy example would be a materials supplier, like tile or brick) then you can still file a lien without a licenese.  

SECTION 29-5-15. Filing requirements; penalty for frivolous lien.

(A) To file a mechanics' lien, a contractor must provide the county clerk of court or register of deeds proof that he is licensed or registered if he is required by law to be licensed or registered. As proof of licensure or registration, the contractor must record his contractor license number or registration number on the lien document when the lien document is filed.

(B) A contractor who files a frivolous lien is subject to a fine up to five thousand dollars, the loss of his registration or contractor license, or both.