How do you define and lock the scope of a project before starting?

Before work begins we run a free 30-minute discovery audit that produces a written scope document: pages, features, integrations, language requirements, and timeline. Both parties sign off on this document before the 50% kickoff payment. The scope is then fixed—if requirements change after sign-off, we quote the delta separately. This protects you from overruns and protects us from scope creep.