Every claim for payment shall be made in writing to the Secretary of State on the form approved by him, or in such other manner, being in writing, as he may accept as sufficient in the circumstances of any particular case or class of cases.

Any person who has made a claim in accordance with the provisions of this regulation may amend his claim, at any time before a decision has been given thereon, by notice in writing delivered or sent to the Secretary of State, and any claim so amended may be treated as if it had been so amended in the first instance.