AS 2128-1978, is the Progress certificate for use with General Conditions of tendering and Form of tender for lump sum contracts 1978 edition. AS 2124 and related Standards are a set of General Conditions of Contract documents suitable for all types of civil, building, electrical and mechanical plant contracting work. Originally sold in a package of: AS 2124-1978, General conditions of contract; AS 2125-1978, General Conditions of Tendering and Form of tender for lump sum contracts; AS 2126-1978, Form of tender for Schedule of rates contracts; AS 2127-1978, Form of Formal instrument of agreement; and AS 2128-1978, Progress certificate (this Standard).