New Delhi, Aug. 6 -- Nine years after India rolled out its Goods and Services Tax (GST), one philosophy has proven more durable than anything in the architecture of the law: when a taxpayer misses a deadline, it is enforced to the day; when the state misses one, it is extended by notification.

GST has been Independent India's largest fiscal experiment: one tax across all states, touching every citizen in a way that even the 1991 reforms did not. In the early years, extensions owing to 'teething problems' were a necessity, not an indulgence.

That is precisely why their persistence into the later years raises this question: is it a confession of structural unreadiness or an act of self-exemption by the state?

As a tax-return form, GSTR-3...