We investigate whether board-interlocked firms via an audit committee (AC) board member exhibit correlated non-audit service (NAS) purchases, and whether financial reporting quality and future firm performance vary with the amount of correlated NAS purchases from the AC interlock. We find that AC interlocked firms have positively correlated total NAS and three NAS subtypes—Tax, Assurance, and Other—in the overall sample period from 2000 to 2016, and in each of the subperiods pre- and post-SOX (Sarbanes–Oxley Act). Firms with a larger NAS component that is explained by the AC interlock tend to exhibit lower financial reporting quality. We also find evidence that firms with higher AC interlocked NAS purchases are associated with lower future performance, although this association exists only in the pre-SOX period. Overall, the evidence suggests that greater NAS purchases among AC interlocked firms can have a detrimental effect on financial reporting quality and auditor independence. While these detrimental effects are concentrated in the pre-SOX period when there were less restrictions on NAS purchases, we find some evidence that the association with lower financial reporting quality persists in the post-SOX period.