Source: https://www.uspto.gov/web/offices/pac/mpep/s2215.html
Timestamp: 2019-04-20 13:14:16+00:00

Document:
Pursuant to 37 CFR 1.20(c)(1), there are different filing fees for a large entity, a small entity and a micro entity, when filing a request for ex parte reexamination under 35 U.S.C. 302. In order for a requester to pay small entity or micro entity fees, a requester must affirmatively state that it is eligible for small entity or micro entity status (respectively). For example, a requester can affirmatively assert small entity status by checking the appropriate box in line 3 on the transmittal form (PTO/SB/57). However, only a patent owner requester can establish micro entity status. A third party requester cannot establish micro entity status, since a third party requester is not provided for in 37 CFR 1.29. See 37 CFR 1.27 and MPEP §§ 509.02 and 509.03 for more information about establishing small entity status. See 37 CFR 1.29 and MPEP § 509.04et seq. for more information about establishing micro entity status.
If the request for ex parte reexamination under 35 U.S.C. 302 is subsequently denied (see MPEP § 2247 and § 2248), or vacated (see MPEP § 2227 and § 2246, subsection I), a refund in accordance with 37 CFR 1.26(c) will be made to the identified requester. If the request for ex parte reexamination under 35 U.S.C. 302 is found to be incomplete and the defect is not cured (see MPEP § 2227), a refund in accordance with 37 CFR 1.26(a) will be made to the identified requester.

References: § 509
 § 2247
 § 2248
 § 2227
 § 2246
 § 2227