This paper investigates the apparent near-optionality of the perfect auxiliary ha (‘have’) in Swedish. Restrictions on the near-optionality of ha-omission are typically recognized in the previous literature as lexical or structural. The paper scrutinizes the viability of these restrictions by means of corpus data. Most of these restrictions are shown not to hold. Instead, the paper defends the view that the optionality of the perfect auxiliary ha in Swedish is linked to whether the clause it occurs in requires a finite feature or not, and whether ha is the only element that can supply a value for this feature. The phenomenon of ha-omission is accounted for in the syntactic frame work LFG. It is shown that ha can only be omitted if another element in the clause can provide a value for the finite feature.