What is a variation order, and what counts as a variation?

Your subcontract may call it an instruction or a direction instead. Whatever its name, what matters is what it changes. A change usually counts as a variation if it alters the work your subcontract describes, or how, when or where you do it. That covers added or omitted work, a different quality or sequence, changed access and changed working conditions. Your subcontract decides exactly what counts and who has the authority to instruct it. So start by comparing what you are now being asked to do with what you priced. Use the drawings, specification, clarifications, amendments and design duties at the revision your subcontract names, not a tender drawing on its own. Then check who instructed the change and what route your subcontract sets for it. Keep the instruction, the source documents, the quantities affected and any notice or valuation rule together in one file. A change in scope does not on its own prove what you will be paid, or that you get more time. Each of those follows its own route under your subcontract.