May a retainer agreement contain language concerning the matters that will be considered in arriving at a fee, and specifically the following language: "Statements for services and disbursements may be rendered monthly and are payable upon receipt. Any balance remaining unpaid after ninety days of the date of billing will, at the discretion of this firm, bear simple interest at the rate of ten percent per annum."
We do not address here the issue of matters that will be considered and shall be considered by an attorney in setting his fee. These are set forth in other opinions and they are not an issue here. Therefore, for purposes of this opinion it will be assumed that those matters stated in the retainer contract are proper and appropriate. Further, it will not be considered here whether or not ten percent interest is appropriate or proper. Any interest charged would have to be considered reasonable and certainly would have to be within legal limits. Thus, the question here is whether or not an attorney may charge interest on an unpaid balance of attorney's fees.
There is nothing in the code of professional responsibility that prohibits the charging of interest. However, it is clear that there should be a definite understanding between the attorney and the client as to the fee. See, Archer v. Griffith, 390 S.W.2d 735 (Tex. 1964), which states: "[T]he courts, because of the confidential relationship (between the attorney and client), scrutinizes with jealousy all contracts between them for compensation which are made while the relation exists. There is a presumption of unfairness or invalidity attaching to the contract, and the burden of showing its fairness and reasonableness is on the attorney." Id. at 739 (quoting Pomeroy, Equity Jurisprudence ∋960d (5th Ed. 1941).
It has been held that an attorney may accept a reputable credit card in payment of his fee. Certainly most of these companies charge interest and the client would then be paying to the credit card company interest on amounts not promptly paid. Thus, the committee has indirectly held in Opinion 349 (October, 1969) that interest could be charged because it is certainly understood that a credit card company would charge interest. Yet, this is not a direct charge by the attorney and the attorney does not get the benefit of the interest charged. However, the committee now approves the charging of reasonable interest wherein the charge is reasonable and complies with custom and law, and wherein the original fee is set properly and is reasonable. (9-0)
Tex. Comm. On Professional Ethics, Op. 409 (1984)