Except for payments of additional tax (refer 2.10), changes to a claimants tax details can only be made upon receipt of an Employment Declaration form signed by the claimant.  Claimants may send in as many ED forms as they like.  Once a new one is received the one dated previously becomes void (refer 8.1).  All changes are entered in AEMP.CM, page 2 and do not require authorisation.