Client And Architect Agreement. Client's Guide to Engaging an Architect RIBA Publications,Royal Institute of British Architects,2004-05-01.This contract is a flexible agreement where the parties attach architect's scope of service and can be used on any size project. First thing you should check is your contract with the Client, to see if you are obligated to agree to an Assignment of your contract to a 3rd party. The ACA Short Form Architect Client Agreement provides a less cumbersome, but fair and balanced model contract for use on small to medium contracts. Information on the DOL registration process and the portal to register can be found on the DOL's Contractor and Subcontractor website.