28 CFR 24.203: Documentation of fees and expenses.
(a) The application shall be accompanied by full documentation of the fees and expenses, including the cost of any study, engineering report, test, or project, for which an award is sought.
(b) The documentation shall include an affidavit from any attorney, agent, or expert witness representing or appearing in behalf of the party, stating the actual time expended and the rate at which fees and other expenses were computed and describing the specific services performed.
(1) The affidavit shall state the services performed. In order to establish the hourly rate, the affidavit shall state the hourly rate which is billed and paid by the majority of clients during the relevant time periods.
(2) If no hourly rate is paid by the majority of clients because, for instance, the attorney or agent represents most clients on a contingency basis, the attorney or agent shall provide information about two attorneys or agents with similar experience, who perform similar work, stating their hourly rate.
(c) The documentation shall also include a description of any expenses for which reimbursement is sought and a statement of the amounts paid and payable by the applicant or by any other person or entity for the services provided.
(d) The adjudicative officer may require the applicant to provide vouchers, receipts, or other substantiation for any expenses claimed.