It's a prof check every year, like the IR, just without the approaches.
Really? What happened to:
(g) Validity, revalidation, and renewal.
(1) An EIR shall be valid for 1 year.
(2) Applicants for the revalidation of an EIR shall:
(i) pass a proficiency check in an aeroplane within a period of 3 months immediately preceding the expiry date of the rating; or
(ii) within 12 months preceding the expiry date of the rating, complete 6 hours as PIC under IFR and a training flight of at least 1 hour with an instructor holding privileges to provide training for the IR(A) or EIR.
(3) For each alternate subsequent revalidation, the holder of the EIR shall pass a proficiency check in accordance with point (g)(2)(i).