20 C.F.R. § 30.600
May a claimant designate a representative?
(a) The claims process under this part is informal, and OWCP acts as an impartial evaluator of the evidence. A claimant need not be represented to file a claim or receive a payment. Nevertheless, a claimant may appoint one individual to represent his or her interests, but the appointment must be in writing.
(b) There can be only one representative at any one time, so after one representative has been properly appointed, OWCP will not recognize another individual as a representative until the claimant withdraws the authorization of the first individual. In addition, OWCP will recognize only certain types of individuals (see § 30.601). For the purposes of paragraph (b) of this section, a “representative” does not include a person who only has a power of attorney to act on behalf of a claimant.
(c) A properly appointed representative who is recognized by OWCP may make a request or give direction to OWCP regarding the claims process, including a hearing. This authority includes presenting or eliciting evidence, making arguments on facts or the law, and obtaining information from the case file, to the same extent as the claimant.
(1) Any notice requirement contained in this part or EEOICPA is fully satisfied if served on the representative, and has the same force and effect as if sent to the claimant.
(2) A representative does not have authority to sign the Form EE-1 (described in § 30.100(a)) or the Form EE-2 (described in § 30.101(a)) for his or her client. A representative also does not have authority to sign the Form EN-20 (described in § 30.505(c)) for his or her client