What happens if a Kaspa transaction declares a wrong storage mass?

A transaction that commits to an incorrect storage mass is treated as invalid and discarded. The actual storage mass can only be calculated once the network knows exactly which coins (UTXOs) the transaction is spending, so the check happens during contextual validation — when the transaction is examined inside a real block with full knowledge of its inputs. If the computed storage mass does not match what the transaction declared, the transaction is rejected; any block containing such a transaction is disqualified from the selected chain, meaning it does not count toward confirmed history. This rule matters because it ensures no transaction can understate its storage cost to sneak around block limits, keeping the network fair for all participants.