In addition to the charges authorized by Section 18212 or 18212.1 an industrial loan company may contract for and receive an administrative fee, which shall be fully earned immediately upon making the loan, with respect to a loan of a principal amount of not more than two thousand five hundred dollars ($2,500) at a rate not in excess of 5 percent of the principal amount or fifty dollars ($50), whichever is lesser. No administrative fee may be contracted for or received in connection with refinancing a loan unless at least one year has elapsed since receipt of a previous administrative fee paid by the borrower.