No, this is not permitted under the AICPA Code of Conduct. The fee of the firm would have based solely on the success of their task. Under the Code, it is allowed to received payment based on the work they have done but it is not the sole basis for its payment. In this situation, there is no agreed payment except for the success of their task so there will be an opportunity of fraud for the firm here in order to receive the fee. To compensate this problem, the Code did not allow this type of payment terms (the fee is based solely in the success of the tax credits they may earn).